containers: update docs from centos:7 to almalinux:9

Bumps [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action) from 3.3.0 to 3.4.0.
- [Release notes](https://github.com/docker/setup-buildx-action/releases)
- [Commits](d70bba72b1...4fd812986e)

---
updated-dependencies:
- dependency-name: docker/setup-buildx-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/audit.yaml

@@ -28,7 +28,7 @@ jobs:
       run:
         shell: ${{ matrix.system.shell }}
     steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
       with:
         python-version: ${{inputs.python_version}}
@@ -61,7 +61,7 @@ jobs:
           ./share/spack/qa/validate_last_exit.ps1
           spack -d audit externals
           ./share/spack/qa/validate_last_exit.ps1
-    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
+    - uses: codecov/codecov-action@e28ff129e5465c2c0dcc6f003fc735cb6ae0c673
       if: ${{ inputs.with_coverage == 'true' }}
       with:
         flags: unittests,audits

.github/workflows/bootstrap.yml

@@ -37,7 +37,7 @@ jobs:
               make patch unzip which xz python3 python3-devel tree \
               cmake bison
       - name: Checkout
-        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+        uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
         with:
           fetch-depth: 0
       - name: Bootstrap clingo
@@ -53,27 +53,31 @@ jobs:
     runs-on: ${{ matrix.runner }}
     strategy:
       matrix:
-        runner: ['macos-13', 'macos-14', "ubuntu-latest"]
+        runner: ['macos-13', 'macos-14', "ubuntu-latest", "windows-latest"]
     steps:
       - name: Setup macOS
-        if: ${{ matrix.runner != 'ubuntu-latest' }}
+        if: ${{ matrix.runner != 'ubuntu-latest' && matrix.runner != 'windows-latest' }}
         run: |
           brew install cmake bison tree
       - name: Checkout
-        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+        uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
         with:
           fetch-depth: 0
       - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
         with:
           python-version: "3.12"
       - name: Bootstrap clingo
+        env:
+          SETUP_SCRIPT_EXT: ${{ matrix.runner == 'windows-latest' && 'ps1' || 'sh' }}
+          SETUP_SCRIPT_SOURCE: ${{ matrix.runner == 'windows-latest' && './' || 'source ' }}
+          USER_SCOPE_PARENT_DIR: ${{ matrix.runner == 'windows-latest' && '$env:userprofile' || '$HOME' }}
         run: |
-          source share/spack/setup-env.sh
+          ${{ env.SETUP_SCRIPT_SOURCE }}share/spack/setup-env.${{ env.SETUP_SCRIPT_EXT }}
           spack bootstrap disable github-actions-v0.5
           spack bootstrap disable github-actions-v0.4
           spack external find --not-buildable cmake bison
           spack -d solve zlib
-          tree ~/.spack/bootstrap/store/
+          tree ${{ env.USER_SCOPE_PARENT_DIR }}/.spack/bootstrap/store/
 
   gnupg-sources:
     runs-on: ${{ matrix.runner }}
@@ -84,15 +88,13 @@ jobs:
       - name: Setup macOS
         if: ${{ matrix.runner != 'ubuntu-latest' }}
         run: |
-          brew install tree
-          # Remove GnuPG since we want to bootstrap it
-          sudo rm -rf /usr/local/bin/gpg
+          brew install tree gawk
+          sudo rm -rf $(command -v gpg gpg2)
       - name: Setup Ubuntu
         if: ${{ matrix.runner == 'ubuntu-latest' }}
-        run: |
-          sudo rm -rf $(which gpg) $(which gpg2) $(which patchelf)
+        run: sudo rm -rf $(command -v gpg gpg2 patchelf)
       - name: Checkout
-        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+        uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
         with:
           fetch-depth: 0
       - name: Bootstrap GnuPG
@@ -121,7 +123,7 @@ jobs:
         run: |
           sudo rm -rf $(which gpg) $(which gpg2) $(which patchelf)
       - name: Checkout
-        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+        uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
         with:
           fetch-depth: 0
       - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d

.github/workflows/build-containers.yml

@@ -40,8 +40,7 @@ jobs:
         # 1: Platforms to build for
         # 2: Base image (e.g. ubuntu:22.04)
         dockerfile: [[amazon-linux, 'linux/amd64,linux/arm64', 'amazonlinux:2'],
-                     [centos7, 'linux/amd64,linux/arm64,linux/ppc64le', 'centos:7'],
-                     [centos-stream, 'linux/amd64,linux/arm64,linux/ppc64le', 'centos:stream'],
+                     [centos-stream9, 'linux/amd64,linux/arm64,linux/ppc64le', 'centos:stream9'],
                      [leap15, 'linux/amd64,linux/arm64,linux/ppc64le', 'opensuse/leap:15'],
                      [ubuntu-focal, 'linux/amd64,linux/arm64,linux/ppc64le', 'ubuntu:20.04'],
                      [ubuntu-jammy, 'linux/amd64,linux/arm64,linux/ppc64le', 'ubuntu:22.04'],
@@ -56,7 +55,7 @@ jobs:
     if: github.repository == 'spack/spack'
     steps:
       - name: Checkout
-        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+        uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
 
       - uses: docker/metadata-action@8e5442c4ef9f78752691e2d8f8d19755c6f78e81
         id: docker_meta
@@ -94,10 +93,10 @@ jobs:
           path: dockerfiles
 
       - name: Set up QEMU
-        uses: docker/setup-qemu-action@68827325e0b33c7199eb31dd4e31fbe9023e06e3
+        uses: docker/setup-qemu-action@5927c834f5b4fdf503fca6f4c7eccda82949e1ee
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@d70bba72b1f3fd22344832f00baa16ece964efeb
+        uses: docker/setup-buildx-action@4fd812986e6c8c2a69e18311145f9371337f27d4
 
       - name: Log in to GitHub Container Registry
         uses: docker/login-action@e92390c5fb421da1463c202d546fed0ec5c39f20
@@ -114,7 +113,7 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Build & Deploy ${{ matrix.dockerfile[0] }}
-        uses: docker/build-push-action@2cdde995de11925a030ce8070c3d77a52ffcf1c0
+        uses: docker/build-push-action@1a162644f9a7e87d8f4b053101d1d9a712edc18c
         with:
           context: dockerfiles/${{ matrix.dockerfile[0] }}
           platforms: ${{ matrix.dockerfile[1] }}

.github/workflows/ci.yaml

@@ -36,7 +36,7 @@ jobs:
       core: ${{ steps.filter.outputs.core }}
       packages: ${{ steps.filter.outputs.packages }}
     steps:
-      - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+      - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
         if: ${{ github.event_name == 'push' }}
         with:
           fetch-depth: 0
@@ -53,6 +53,13 @@ jobs:
             - 'var/spack/repos/builtin/packages/clingo/**'
             - 'var/spack/repos/builtin/packages/python/**'
             - 'var/spack/repos/builtin/packages/re2c/**'
+            - 'var/spack/repos/builtin/packages/gnupg/**'
+            - 'var/spack/repos/builtin/packages/libassuan/**'
+            - 'var/spack/repos/builtin/packages/libgcrypt/**'
+            - 'var/spack/repos/builtin/packages/libgpg-error/**'
+            - 'var/spack/repos/builtin/packages/libksba/**'
+            - 'var/spack/repos/builtin/packages/npth/**'
+            - 'var/spack/repos/builtin/packages/pinentry/**'
             - 'lib/spack/**'
             - 'share/spack/**'
             - '.github/workflows/bootstrap.yml'
@@ -77,13 +84,8 @@ jobs:
     needs: [ prechecks, changes ]
     uses: ./.github/workflows/unit_tests.yaml
     secrets: inherit
-  windows:
-    if: ${{ github.repository == 'spack/spack' && needs.changes.outputs.core == 'true' }}
-    needs: [ prechecks ]
-    uses: ./.github/workflows/windows_python.yml
-    secrets: inherit
   all:
-    needs: [ windows, unit-tests, bootstrap ]
+    needs: [ unit-tests, bootstrap ]
     runs-on: ubuntu-latest
     steps:
     - name: Success

.github/workflows/nightly-win-builds.yml

@@ -14,7 +14,7 @@ jobs:
   build-paraview-deps:
     runs-on: windows-latest
     steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
       with:
         fetch-depth: 0
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d

.github/workflows/style/requirements.txt

@@ -1,7 +1,7 @@
 black==24.4.2
 clingo==5.7.1
-flake8==7.0.0
+flake8==7.1.0
 isort==5.13.2
 mypy==1.8.0
-types-six==1.16.21.9
+types-six==1.16.21.20240513
 vermin==1.6.0

.github/workflows/unit_tests.yaml

@@ -51,7 +51,7 @@ jobs:
           on_develop: false
 
     steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
       with:
         fetch-depth: 0
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
@@ -91,7 +91,7 @@ jobs:
           UNIT_TEST_COVERAGE: ${{ matrix.python-version == '3.11' }}
       run: |
           share/spack/qa/run-unit-tests
-    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
+    - uses: codecov/codecov-action@e28ff129e5465c2c0dcc6f003fc735cb6ae0c673
       with:
         flags: unittests,linux,${{ matrix.concretizer }}
         token: ${{ secrets.CODECOV_TOKEN }}
@@ -100,7 +100,7 @@ jobs:
   shell:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
       with:
         fetch-depth: 0
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
@@ -124,7 +124,7 @@ jobs:
           COVERAGE: true
       run: |
           share/spack/qa/run-shell-tests
-    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
+    - uses: codecov/codecov-action@e28ff129e5465c2c0dcc6f003fc735cb6ae0c673
       with:
         flags: shelltests,linux
         token: ${{ secrets.CODECOV_TOKEN }}
@@ -141,7 +141,7 @@ jobs:
           dnf install -y \
               bzip2 curl file gcc-c++ gcc gcc-gfortran git gnupg2 gzip \
               make patch tcl unzip which xz
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
     - name: Setup repo and non-root user
       run: |
           git --version
@@ -160,7 +160,7 @@ jobs:
   clingo-cffi:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
       with:
         fetch-depth: 0
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
@@ -185,7 +185,7 @@ jobs:
           SPACK_TEST_SOLVER: clingo
       run: |
           share/spack/qa/run-unit-tests
-    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
+    - uses: codecov/codecov-action@e28ff129e5465c2c0dcc6f003fc735cb6ae0c673
       with:
         flags: unittests,linux,clingo
         token: ${{ secrets.CODECOV_TOKEN }}
@@ -195,10 +195,10 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [macos-latest, macos-14]
+        os: [macos-13, macos-14]
         python-version: ["3.11"]
     steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
       with:
         fetch-depth: 0
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
@@ -223,8 +223,39 @@ jobs:
         $(which spack) solve zlib
         common_args=(--dist loadfile --tx '4*popen//python=./bin/spack-tmpconfig python -u ./bin/spack python' -x)
         $(which spack) unit-test --verbose --cov --cov-config=pyproject.toml --cov-report=xml:coverage.xml "${common_args[@]}"
-    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
+    - uses: codecov/codecov-action@e28ff129e5465c2c0dcc6f003fc735cb6ae0c673
       with:
         flags: unittests,macos
         token: ${{ secrets.CODECOV_TOKEN }}
         verbose: true
+  # Run unit tests on Windows
+  windows:
+    defaults:
+      run:
+        shell:
+          powershell Invoke-Expression -Command "./share/spack/qa/windows_test_setup.ps1"; {0}
+    runs-on: windows-latest
+    steps:
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
+      with:
+        fetch-depth: 0
+    - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
+      with:
+        python-version: 3.9
+    - name: Install Python packages
+      run: |
+          python -m pip install --upgrade pip pywin32 setuptools pytest-cov clingo
+    - name: Create local develop
+      run: |
+        ./.github/workflows/setup_git.ps1
+    - name: Unit Test
+      run: |
+        spack unit-test -x --verbose --cov --cov-config=pyproject.toml
+        ./share/spack/qa/validate_last_exit.ps1
+        coverage combine -a
+        coverage xml
+    - uses: codecov/codecov-action@e28ff129e5465c2c0dcc6f003fc735cb6ae0c673
+      with:
+        flags: unittests,windows
+        token: ${{ secrets.CODECOV_TOKEN }}
+        verbose: true

.github/workflows/valid-style.yml

@@ -18,7 +18,7 @@ jobs:
   validate:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
       with:
         python-version: '3.11'
@@ -35,7 +35,7 @@ jobs:
   style:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
       with:
         fetch-depth: 0
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
@@ -70,7 +70,7 @@ jobs:
           dnf install -y \
               bzip2 curl file gcc-c++ gcc gcc-gfortran git gnupg2 gzip \
               make patch tcl unzip which xz
-      - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+      - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
       - name: Setup repo and non-root user
         run: |
           git --version

.github/workflows/windows_python.yml

@@ -1,83 +0,0 @@
-name: windows
-
-on:
-  workflow_call:
-
-concurrency:
-  group: windows-${{github.ref}}-${{github.event.pull_request.number || github.run_number}}
-  cancel-in-progress: true
-
-defaults:
-  run:
-    shell:
-     powershell Invoke-Expression -Command "./share/spack/qa/windows_test_setup.ps1"; {0}
-jobs:
-  unit-tests:
-    runs-on: windows-latest
-    steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
-      with:
-        fetch-depth: 0
-    - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
-      with:
-        python-version: 3.9
-    - name: Install Python packages
-      run: |
-          python -m pip install --upgrade pip pywin32 setuptools pytest-cov clingo
-    - name: Create local develop
-      run: |
-        ./.github/workflows/setup_git.ps1
-    - name: Unit Test
-      run: |
-        spack unit-test -x --verbose --cov --cov-config=pyproject.toml --ignore=lib/spack/spack/test/cmd
-        ./share/spack/qa/validate_last_exit.ps1
-        coverage combine -a
-        coverage xml
-    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
-      with:
-        flags: unittests,windows
-        token: ${{ secrets.CODECOV_TOKEN }}
-        verbose: true
-  unit-tests-cmd:
-    runs-on: windows-latest
-    steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
-      with:
-        fetch-depth: 0
-    - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
-      with:
-        python-version: 3.9
-    - name: Install Python packages
-      run: |
-          python -m pip install --upgrade pip pywin32 setuptools coverage pytest-cov clingo
-    - name: Create local develop
-      run: |
-        ./.github/workflows/setup_git.ps1
-    - name: Command Unit Test
-      run: |
-        spack unit-test -x --verbose --cov --cov-config=pyproject.toml lib/spack/spack/test/cmd
-        ./share/spack/qa/validate_last_exit.ps1
-        coverage combine -a
-        coverage xml
-    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
-      with:
-        flags: unittests,windows
-        token: ${{ secrets.CODECOV_TOKEN }}
-        verbose: true
-  build-abseil:
-    runs-on: windows-latest
-    steps:
-    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
-      with:
-        fetch-depth: 0
-    - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
-      with:
-        python-version: 3.9
-    - name: Install Python packages
-      run: |
-          python -m pip install --upgrade pip pywin32 setuptools coverage
-    - name: Build Test
-      run: |
-        spack compiler find
-        spack -d external find cmake ninja
-        spack -d install abseil-cpp

CHANGELOG.md

@@ -1,3 +1,369 @@
+
+# v0.22.0 (2024-05-12)
+
+`v0.22.0` is a major feature release.
+
+## Features in this release
+
+1. **Compiler dependencies**
+
+    We are in the process of making compilers proper dependencies in Spack, and a number
+    of changes in `v0.22` support that effort. You may notice nodes in your dependency
+    graphs for compiler runtime libraries like `gcc-runtime` or `libgfortran`, and you
+    may notice that Spack graphs now include `libc`. We've also begun moving compiler
+    configuration from `compilers.yaml` to `packages.yaml` to make it consistent with
+    other externals. We are trying to do this with the least disruption possible, so
+    your existing `compilers.yaml` files should still work. We expect to be done with
+    this transition by the `v0.23` release in November.
+
+    * #41104: Packages compiled with `%gcc` on Linux, macOS and FreeBSD now depend on a
+      new package `gcc-runtime`, which contains a copy of the shared compiler runtime
+      libraries. This enables gcc runtime libraries to be installed and relocated when
+      using a build cache. When building minimal Spack-generated container images it is
+      no longer necessary to install libgfortran, libgomp etc. using the system package
+      manager.
+
+    * #42062: Packages compiled with `%oneapi` now depend on a new package
+      `intel-oneapi-runtime`. This is similar to `gcc-runtime`, and the runtimes can
+      provide virtuals and compilers can inject dependencies on virtuals into compiled
+      packages. This allows us to model library soname compatibility and allows
+      compilers like `%oneapi` to provide virtuals like `sycl` (which can also be
+      provided by standalone libraries). Note that until we have an agreement in place
+      with intel, Intel packages are marked `redistribute(source=False, binary=False)`
+      and must be downloaded outside of Spack.
+
+    * #43272: changes to the optimization criteria of the solver improve the hit-rate of
+      buildcaches by a fair amount. The solver more relaxed compatibility rules and will
+      not try to strictly match compilers or targets of reused specs. Users can still
+      enforce the previous strict behavior with `require:` sections in `packages.yaml`.
+      Note that to enforce correct linking, Spack will *not* reuse old `%gcc` and
+      `%oneapi` specs that do not have the runtime libraries as a dependency.
+
+    * #43539: Spack will reuse specs built with compilers that are *not* explicitly
+      configured in `compilers.yaml`. Because we can now keep runtime libraries in build
+      cache, we do not require you to also have a local configured compiler to *use* the
+      runtime libraries. This improves reuse in buildcaches and avoids conflicts with OS
+      updates that happen underneath Spack.
+
+    * #43190: binary compatibility on `linux` is now based on the `libc` version,
+      instead of on the `os` tag. Spack builds now detect the host `libc` (`glibc` or
+      `musl`) and add it as an implicit external node in the dependency graph. Binaries
+      with a `libc` with the same name and a version less than or equal to that of the
+      detected `libc` can be reused. This is only on `linux`, not `macos` or `Windows`.
+
+    * #43464: each package that can provide a compiler is now detectable using `spack
+      external find`. External packages defining compiler paths are effectively used as
+      compilers, and `spack external find -t compiler` can be used as a substitute for
+      `spack compiler find`. More details on this transition are in
+      [the docs](https://spack.readthedocs.io/en/latest/getting_started.html#manual-compiler-configuration)
+
+2. **Improved `spack find` UI for Environments**
+
+   If you're working in an enviroment, you likely care about:
+
+   * What are the roots
+   * Which ones are installed / not installed
+   * What's been added that still needs to be concretized
+
+    We've tweaked `spack find` in environments to show this information much more
+    clearly. Installation status is shown next to each root, so you can see what is
+    installed. Roots are also shown in bold in the list of installed packages. There is
+    also a new option for `spack find -r` / `--only-roots` that will only show env
+    roots, if you don't want to look at all the installed specs.
+
+    More details in #42334.
+
+3. **Improved command-line string quoting**
+
+   We are making some breaking changes to how Spack parses specs on the CLI in order to
+   respect shell quoting instead of trying to fight it. If you (sadly) had to write
+   something like this on the command line:
+
+    ```
+    spack install zlib cflags=\"-O2 -g\"
+    ```
+
+    That will now result in an error, but you can now write what you probably expected
+    to work in the first place:
+
+    ```
+    spack install zlib cflags="-O2 -g"
+    ```
+
+    Quoted can also now include special characters, so you can supply flags like:
+
+    ```
+    spack intall zlib ldflags='-Wl,-rpath=$ORIGIN/_libs'
+    ```
+
+    To reduce ambiguity in parsing, we now require that you *not* put spaces around `=`
+    and `==` when for flags or variants. This would not have broken before but will now
+    result in an error:
+
+    ```
+    spack install zlib cflags = "-O2 -g"
+    ```
+
+    More details and discussion in #30634.
+
+4. **Revert default `spack install` behavior to `--reuse`**
+
+   We changed the default concretizer behavior from `--reuse` to `--reuse-deps` in
+   #30990 (in `v0.20`), which meant that *every* `spack install` invocation would
+   attempt to build a new version of the requested package / any environment roots.
+   While this is a common ask for *upgrading* and for *developer* workflows, we don't
+   think it should be the default for a package manager.
+
+   We are going to try to stick to this policy:
+   1. Prioritize reuse and build as little as possible by default.
+   2. Only upgrade or install duplicates if they are explicitly asked for, or if there
+      is a known security issue that necessitates an upgrade.
+
+   With the install command you now have three options:
+
+   * `--reuse` (default): reuse as many existing installations as possible.
+   * `--reuse-deps` / `--fresh-roots`: upgrade (freshen) roots but reuse dependencies if possible.
+   * `--fresh`: install fresh versions of requested packages (roots) and their dependencies.
+
+   We've also introduced `--fresh-roots` as an alias for `--reuse-deps` to make it more clear
+   that it may give you fresh versions. More details in #41302 and #43988.
+
+5. **More control over reused specs**
+
+   You can now control which packages to reuse and how. There is a new
+   `concretizer:reuse` config option, which accepts the following properties:
+
+   - `roots`: `true` to reuse roots, `false` to reuse just dependencies
+   - `exclude`: list of constraints used to select which specs *not* to reuse
+   - `include`: list of constraints used to select which specs *to* reuse
+   - `from`: list of sources for reused specs (some combination of `local`,
+     `buildcache`, or `external`)
+
+   For example, to reuse only specs compiled with GCC, you could write:
+
+   ```yaml
+   concretizer:
+      reuse:
+        roots: true
+        include:
+        - "%gcc"
+   ```
+
+   Or, if `openmpi` must be used from externals, and it must be the only external used:
+
+   ```yaml
+   concretizer:
+     reuse:
+       roots: true
+       from:
+       - type: local
+         exclude: ["openmpi"]
+       - type: buildcache
+         exclude: ["openmpi"]
+       - type: external
+         include: ["openmpi"]
+   ```
+
+6. **New `redistribute()` directive**
+
+   Some packages can't be redistributed in source or binary form. We need an explicit
+   way to say that in a package.
+
+   Now there is a `redistribute()` directive so that package authors can write:
+
+   ```python
+   class MyPackage(Package):
+       redistribute(source=False, binary=False)
+   ```
+
+   Like other directives, this works with `when=`:
+
+   ```python
+   class MyPackage(Package):
+       # 12.0 and higher are proprietary
+       redistribute(source=False, binary=False, when="@12.0:")
+
+       # can't redistribute when we depend on some proprietary dependency
+       redistribute(source=False, binary=False, when="^proprietary-dependency")
+   ```
+
+    More in #20185.
+
+7. **New `conflict:` and `prefer:` syntax for package preferences**
+
+   Previously, you could express conflicts and preferences in `packages.yaml` through
+   some contortions with `require:`:
+
+    ```yaml
+    packages:
+      zlib-ng:
+        require:
+        - one_of: ["%clang", "@:"]   # conflict on %clang
+        - any_of: ["+shared", "@:"]  # strong preference for +shared
+    ```
+
+    You can now use `require:` and `prefer:` for a much more readable configuration:
+
+    ```yaml
+    packages:
+      zlib-ng:
+        conflict:
+        - "%clang"
+        prefer:
+        - "+shared"
+    ```
+
+    See [the documentation](https://spack.readthedocs.io/en/latest/packages_yaml.html#conflicts-and-strong-preferences)
+    and #41832 for more details.
+
+8. **`include_concrete` in environments**
+
+   You may want to build on the *concrete* contents of another environment without
+   changing that environment.  You can now include the concrete specs from another
+   environment's `spack.lock` with `include_concrete`:
+
+   ```yaml
+      spack:
+        specs: []
+        concretizer:
+            unify: true
+        include_concrete:
+        - /path/to/environment1
+        - /path/to/environment2
+   ```
+
+   Now, when *this* environment is concretized, it will bring in the already concrete
+   specs from `environment1` and `environment2`, and build on top of them without
+   changing them. This is useful if you have phased deployments, where old deployments
+   should not be modified but you want to use as many of them as possible. More details
+   in #33768.
+
+9. **`python-venv` isolation**
+
+   Spack has unique requirements for Python because it:
+    1. installs every package in its own independent directory, and
+    2. allows users to register *external* python installations.
+
+   External installations may contain their own installed packages that can interfere
+   with Spack installations, and some distributions (Debian and Ubuntu) even change the
+   `sysconfig` in ways that alter the installation layout of installed Python packages
+   (e.g., with the addition of a `/local` prefix on Debian or Ubuntu). To isolate Spack
+   from these and other issues, we now insert a small `python-venv` package in between
+   `python` and packages that need to install Python code. This isolates Spack's build
+   environment, isolates Spack from any issues with an external python, and resolves a
+   large number of issues we've had with Python installations.
+
+   See #40773 for further details.
+
+## New commands, options, and directives
+
+* Allow packages to be pushed to build cache after install from source (#42423)
+* `spack develop`: stage build artifacts in same root as non-dev builds #41373
+  * Don't delete `spack develop` build artifacts after install (#43424)
+* `spack find`: add options for local/upstream only (#42999)
+* `spack logs`: print log files for packages (either partially built or installed) (#42202)
+* `patch`: support reversing patches (#43040)
+* `develop`: Add -b/--build-directory option to set build_directory package attribute (#39606)
+* `spack list`: add `--namesapce` / `--repo` option (#41948)
+* directives: add `checked_by` field to `license()`, add some license checks
+* `spack gc`: add options for environments and build dependencies (#41731)
+* Add `--create` to `spack env activate` (#40896)
+
+## Performance improvements
+
+* environment.py: fix excessive re-reads (#43746)
+* ruamel yaml: fix quadratic complexity bug  (#43745)
+* Refactor to improve `spec format` speed (#43712)
+* Do not acquire a write lock on the env post install if no views (#43505)
+* asp.py: fewer calls to `spec.copy()` (#43715)
+* spec.py: early return in `__str__`
+* avoid `jinja2` import at startup unless needed (#43237)
+
+## Other new features of note
+
+* `archspec`: update to `v0.2.4`: support for Windows, bugfixes for `neoverse-v1` and
+  `neoverse-v2` detection.
+* `spack config get`/`blame`: with no args, show entire config
+* `spack env create <env>`: dir if dir-like (#44024)
+* ASP-based solver: update os compatibility for macOS (#43862)
+* Add handling of custom ssl certs in urllib ops (#42953)
+* Add ability to rename environments (#43296)
+* Add config option and compiler support to reuse across OS's (#42693)
+* Support for prereleases (#43140)
+* Only reuse externals when configured (#41707)
+* Environments: Add support for including views (#42250)
+
+## Binary caches
+* Build cache: make signed/unsigned a mirror property (#41507)
+* tools stack
+
+## Removals, deprecations, and syntax changes
+* remove `dpcpp` compiler and package (#43418)
+* spack load: remove --only argument (#42120)
+
+## Notable Bugfixes
+* repo.py: drop deleted packages from provider cache (#43779)
+* Allow `+` in module file names (#41999)
+* `cmd/python`: use runpy to allow multiprocessing in scripts (#41789)
+* Show extension commands with spack -h (#41726)
+* Support environment variable expansion inside module projections (#42917)
+* Alert user to failed concretizations (#42655)
+* shell: fix zsh color formatting for PS1 in environments (#39497)
+* spack mirror create --all: include patches (#41579)
+
+## Spack community stats
+
+* 7,994 total packages; 525 since `v0.21.0`
+    * 178 new Python packages, 5 new R packages
+* 358 people contributed to this release
+    * 344 committers to packages
+    * 45 committers to core
+
+# v0.21.2 (2024-03-01)
+
+## Bugfixes
+
+- Containerize: accommodate nested or pre-existing spack-env paths (#41558)
+- Fix setup-env script, when going back and forth between instances (#40924)
+- Fix using fully-qualified namespaces from root specs (#41957)
+- Fix a bug when a required provider is requested for multiple virtuals (#42088)
+- OCI buildcaches:
+  - only push in parallel when forking (#42143)
+  - use pickleable errors (#42160)
+- Fix using sticky variants in externals (#42253)
+- Fix a rare issue with conditional requirements and multi-valued variants (#42566)
+
+## Package updates
+- rust: add v1.75, rework a few variants (#41161,#41903)
+- py-transformers: add v4.35.2 (#41266)
+- mgard: fix OpenMP on AppleClang (#42933)
+
+# v0.21.1 (2024-01-11)
+
+## New features
+- Add support for reading buildcaches created by Spack v0.22 (#41773)
+
+## Bugfixes
+
+- spack graph: fix coloring with environments (#41240)
+- spack info: sort variants in --variants-by-name (#41389)
+- Spec.format: error on old style format strings (#41934)
+- ASP-based solver: 
+  - fix infinite recursion when computing concretization errors (#41061)
+  - don't error for type mismatch on preferences (#41138)
+  - don't emit spurious debug output (#41218)
+- Improve the error message for deprecated preferences (#41075)
+- Fix MSVC preview version breaking clingo build on Windows (#41185)
+- Fix multi-word aliases (#41126)
+- Add a warning for unconfigured compiler (#41213)
+- environment: fix an issue with deconcretization/reconcretization of specs (#41294)
+- buildcache: don't error if a patch is missing, when installing from binaries (#41986)
+- Multiple improvements to unit-tests (#41215,#41369,#41495,#41359,#41361,#41345,#41342,#41308,#41226)
+
+## Package updates
+- root: add a webgui patch to address security issue (#41404)
+- BerkeleyGW: update source urls (#38218)
+
 # v0.21.0 (2023-11-11)
 
 `v0.21.0` is a major feature release.

README.md

@@ -32,7 +32,7 @@
 
 Spack is a multi-platform package manager that builds and installs
 multiple versions and configurations of software. It works on Linux,
-macOS, and many supercomputers. Spack is non-destructive: installing a
+macOS, Windows, and many supercomputers. Spack is non-destructive: installing a
 new version of a package does not break existing installations, so many
 configurations of the same package can coexist.
 

bin/spack-python

@@ -22,4 +22,4 @@
 #
 # This is compatible across platforms.
 #
-exec /usr/bin/env spack python "$@"
+exec spack python "$@"

bin/spack.bat

@@ -188,25 +188,27 @@ if NOT "%_sp_args%"=="%_sp_args:--help=%" (
 goto :end_switch
 
 :case_load
-:: If args contain --sh, --csh, or -h/--help: just execute.
-if defined _sp_args (
-    if NOT "%_sp_args%"=="%_sp_args:--help=%" (
-        goto :default_case
-    ) else if NOT "%_sp_args%"=="%_sp_args:-h=%" (
-        goto :default_case
-    ) else if NOT "%_sp_args%"=="%_sp_args:--bat=%" (
-        goto :default_case
-    )
+if NOT defined _sp_args (
+   exit /B 0
+)
+
+:: If args contain --bat, or -h/--help: just execute.
+if NOT "%_sp_args%"=="%_sp_args:--help=%" (
+    goto :default_case
+) else if NOT "%_sp_args%"=="%_sp_args:-h=%" (
+    goto :default_case
+) else if NOT "%_sp_args%"=="%_sp_args:--bat=%" (
+    goto :default_case
+) else if NOT "%_sp_args%"=="%_sp_args:--list=%" (
+    goto :default_case
 )
 
 for /f "tokens=* USEBACKQ" %%I in (
-    `python "%spack%" %_sp_flags% %_sp_subcommand% --bat %_sp_args%`) do %%I
+    `python "%spack%" %_sp_flags% %_sp_subcommand% --bat %_sp_args%`
+    ) do %%I
 
 goto :end_switch
 
-:case_unload
-goto :case_load
-
 :default_case
 python "%spack%" %_sp_flags% %_sp_subcommand% %_sp_args%
 goto :end_switch

bin/spack.ps1

@@ -144,3 +144,5 @@ switch($SpackSubCommand)
     "unload" {Invoke-SpackLoad}
     default  {python "$Env:SPACK_ROOT/bin/spack" $SpackCMD_params $SpackSubCommand $SpackSubCommandArgs}
 }
+
+exit $LASTEXITCODE

etc/spack/defaults/cray/modules.yaml

@@ -1,16 +0,0 @@
-# -------------------------------------------------------------------------
-# This is the default configuration for Spack's module file generation.
-#
-# Settings here are versioned with Spack and are intended to provide
-# sensible defaults out of the box. Spack maintainers should edit this
-# file to keep it current.
-#
-# Users can override these settings by editing the following files.
-#
-# Per-spack-instance settings (overrides defaults):
-#   $SPACK_ROOT/etc/spack/modules.yaml
-#
-# Per-user settings (overrides default and site settings):
-#   ~/.spack/modules.yaml
-# -------------------------------------------------------------------------
-modules: {}

etc/spack/defaults/cray/packages.yaml

@@ -1,19 +0,0 @@
-# -------------------------------------------------------------------------
-# This file controls default concretization preferences for Spack.
-#
-# Settings here are versioned with Spack and are intended to provide
-# sensible defaults out of the box. Spack maintainers should edit this
-# file to keep it current.
-#
-# Users can override these settings by editing the following files.
-#
-# Per-spack-instance settings (overrides defaults):
-#   $SPACK_ROOT/etc/spack/packages.yaml
-#
-# Per-user settings (overrides default and site settings):
-#   ~/.spack/packages.yaml
-# -------------------------------------------------------------------------
-packages:
-  all:
-    providers:
-      iconv: [glibc, musl, libiconv]

etc/spack/defaults/linux/packages.yaml

@@ -1,19 +1,3 @@
-# -------------------------------------------------------------------------
-# This file controls default concretization preferences for Spack.
-#
-# Settings here are versioned with Spack and are intended to provide
-# sensible defaults out of the box. Spack maintainers should edit this
-# file to keep it current.
-#
-# Users can override these settings by editing the following files.
-#
-# Per-spack-instance settings (overrides defaults):
-#   $SPACK_ROOT/etc/spack/packages.yaml
-#
-# Per-user settings (overrides default and site settings):
-#   ~/.spack/packages.yaml
-# -------------------------------------------------------------------------
 packages:
-  all:
-    providers:
-      iconv: [glibc, musl, libiconv]
+  iconv:
+    require: [libiconv]

etc/spack/defaults/packages.yaml

@@ -38,10 +38,9 @@ packages:
       lapack: [openblas, amdlibflame]
       libc: [glibc, musl]
       libgfortran: [ gcc-runtime ]
-      libglx: [mesa+glx, mesa18+glx]
+      libglx: [mesa+glx]
       libifcore: [ intel-oneapi-runtime ]
       libllvm: [llvm]
-      libosmesa: [mesa+osmesa, mesa18+osmesa]
       lua-lang: [lua, lua-luajit-openresty, lua-luajit]
       luajit: [lua-luajit-openresty, lua-luajit]
       mariadb-client: [mariadb-c-client, mariadb]

lib/spack/docs/basic_usage.rst

@@ -1433,22 +1433,12 @@ the reserved keywords ``platform``, ``os`` and ``target``:
    $ spack install libelf os=ubuntu18.04
    $ spack install libelf target=broadwell
 
-or together by using the reserved keyword ``arch``:
-
-.. code-block:: console
-
-   $ spack install libelf arch=cray-CNL10-haswell
-
 Normally users don't have to bother specifying the architecture if they
 are installing software for their current host, as in that case the
 values will be detected automatically.  If you need fine-grained control
 over which packages use which targets (or over *all* packages' default
 target), see :ref:`package-preferences`.
 
-.. admonition:: Cray machines
-
-  The situation is a little bit different for Cray machines and a detailed
-  explanation on how the architecture can be set on them can be found at :ref:`cray-support`
 
 .. _support-for-microarchitectures:
 

lib/spack/docs/build_systems/autotoolspackage.rst

@@ -147,6 +147,15 @@ example, the ``bash`` shell is used to run the ``autogen.sh`` script.
    def autoreconf(self, spec, prefix):
        which("bash")("autogen.sh")
 
+If the ``package.py`` has build instructions in a separate
+:ref:`builder class <multiple_build_systems>`, the signature for a phase changes slightly:
+
+.. code-block:: python
+
+   class AutotoolsBuilder(AutotoolsBuilder):
+      def autoreconf(self, pkg, spec, prefix):
+         which("bash")("autogen.sh")
+
 """""""""""""""""""""""""""""""""""""""
 patching configure or Makefile.in files
 """""""""""""""""""""""""""""""""""""""

lib/spack/docs/build_systems/inteloneapipackage.rst

@@ -25,7 +25,7 @@ use Spack to build packages with the tools.
 The Spack Python class ``IntelOneapiPackage`` is a base class that is
 used by ``IntelOneapiCompilers``, ``IntelOneapiMkl``,
 ``IntelOneapiTbb`` and other classes to implement the oneAPI
-packages. Search for ``oneAPI`` at `<packages.spack.io>`_ for the full
+packages. Search for ``oneAPI`` at `packages.spack.io <https://packages.spack.io>`_ for the full
 list of available oneAPI packages, or use::
 
   spack list -d oneAPI

lib/spack/docs/chain.rst

@@ -11,7 +11,8 @@ Chaining Spack Installations
 
 You can point your Spack installation to another installation to use any
 packages that are installed there. To register the other Spack instance,
-you can add it as an entry to ``upstreams.yaml``:
+you can add it as an entry to ``upstreams.yaml`` at any of the
+:ref:`configuration-scopes`:
 
 .. code-block:: yaml
 
@@ -22,7 +23,8 @@ you can add it as an entry to ``upstreams.yaml``:
       install_tree: /path/to/another/spack/opt/spack
 
 ``install_tree`` must point to the ``opt/spack`` directory inside of the
-Spack base directory.
+Spack base directory, or the location of the ``install_tree`` defined
+in :ref:`config.yaml <config-yaml>`.
 
 Once the upstream Spack instance has been added, ``spack find`` will
 automatically check the upstream instance when querying installed packages,

lib/spack/docs/containers.rst

@@ -203,12 +203,9 @@ The OS that are currently supported are summarized in the table below:
    * - Ubuntu 24.04
      - ``ubuntu:24.04``
      - ``spack/ubuntu-noble``
-   * - CentOS 7
-     - ``centos:7``
-     - ``spack/centos7``
-   * - CentOS Stream
-     - ``quay.io/centos/centos:stream``
-     - ``spack/centos-stream``
+   * - CentOS Stream9
+     - ``quay.io/centos/centos:stream9``
+     - ``spack/centos-stream9``
    * - openSUSE Leap
      - ``opensuse/leap``
      - ``spack/leap15``
@@ -273,7 +270,7 @@ under the ``container`` attribute of environments:
        # Sets the base images for the stages where Spack builds the
        # software or where the software gets installed after being built..
        images:
-         os: "centos:7"
+         os: "almalinux:9"
          spack: develop
 
        # Whether or not to strip binaries
@@ -324,32 +321,33 @@ following ``spack.yaml``:
 
      container:
        images:
-         os: centos:7
-         spack: 0.15.4
+         os: almalinux:9
+         spack: 0.22.0
 
-uses ``spack/centos7:0.15.4``  and ``centos:7`` for the stages where the
+uses ``spack/almalinux9:0.22.0``  and ``almalinux:9`` for the stages where the
 software is respectively built and installed:
 
 .. code-block:: docker
 
    # Build stage with Spack pre-installed and ready to be used
-   FROM spack/centos7:0.15.4 as builder
+   FROM spack/almalinux9:0.22.0 AS builder
 
    # What we want to install and how we want to install it
    # is specified in a manifest file (spack.yaml)
-   RUN mkdir /opt/spack-environment \
-   &&  (echo "spack:" \
-   &&   echo "  specs:" \
-   &&   echo "  - gromacs+mpi" \
-   &&   echo "  - mpich" \
-   &&   echo "  concretizer:" \
-   &&   echo "    unify: true" \
-   &&   echo "  config:" \
-   &&   echo "    install_tree: /opt/software" \
-   &&   echo "  view: /opt/view") > /opt/spack-environment/spack.yaml
+   RUN mkdir -p /opt/spack-environment && \
+   set -o noclobber \
+   &&  (echo spack: \
+   &&   echo '  specs:' \
+   &&   echo '  - gromacs+mpi' \
+   &&   echo '  - mpich' \
+   &&   echo '  concretizer:' \
+   &&   echo '    unify: true' \
+   &&   echo '  config:' \
+   &&   echo '    install_tree: /opt/software' \
+   &&   echo '  view: /opt/views/view') > /opt/spack-environment/spack.yaml
    [ ... ]
    # Bare OS image to run the installed executables
-   FROM centos:7
+   FROM quay.io/almalinuxorg/almalinux:9
 
    COPY --from=builder /opt/spack-environment /opt/spack-environment
    COPY --from=builder /opt/software /opt/software

lib/spack/docs/environments.rst

@@ -460,6 +460,125 @@ Sourcing that file in Bash will make the environment available to the
 user; and can be included in ``.bashrc`` files, etc.  The ``loads``
 file may also be copied out of the environment, renamed, etc.
 
+
+.. _environment_include_concrete:
+
+------------------------------
+Included Concrete Environments
+------------------------------
+
+Spack environments can create an environment based off of information in already
+established environments. You can think of it as a combination of existing
+environments. It will gather information from the existing environment's
+``spack.lock`` and use that during the creation of this included concrete
+environment. When an included concrete environment is created it will generate
+a ``spack.lock`` file for the newly created environment.
+
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Creating included environments
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+To create a combined concrete environment, you must have at least one existing
+concrete environment. You will use the command ``spack env create`` with the
+argument ``--include-concrete`` followed by the name or path of the environment
+you'd like to include. Here is an example of how to create a combined environment
+from the command line.
+
+.. code-block:: console
+
+   $ spack env create myenv
+   $ spack -e myenv add python
+   $ spack -e myenv concretize
+   $ spack env create --include-concrete myenv included_env
+
+
+You can also include an environment directly in the ``spack.yaml`` file. It
+involves adding the ``include_concrete`` heading in the yaml followed by the
+absolute path to the independent environments.
+
+.. code-block:: yaml
+
+   spack:
+     specs: []
+     concretizer:
+         unify: true
+     include_concrete:
+     - /absolute/path/to/environment1
+     - /absolute/path/to/environment2
+
+
+Once the ``spack.yaml`` has been updated you must concretize the environment to
+get the concrete specs from the included environments.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Updating an included environment
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+If changes were made to the base environment and you want that reflected in the
+included environment you will need to reconcretize both the base environment and the
+included environment for the change to be implemented. For example:
+
+.. code-block:: console
+
+   $ spack env create myenv
+   $ spack -e myenv add python
+   $ spack -e myenv concretize
+   $ spack env create --include-concrete myenv included_env
+
+
+   $ spack -e myenv find
+   ==> In environment myenv
+   ==> Root specs
+   python
+
+   ==> 0 installed packages
+
+
+   $ spack -e included_env find
+   ==> In environment included_env
+   ==> No root specs
+   ==> Included specs
+   python
+
+   ==> 0 installed packages
+
+Here we see that ``included_env`` has access to the python package through
+the ``myenv`` environment. But if we were to add another spec to ``myenv``,
+``included_env`` will not be able to access the new information.
+
+.. code-block:: console
+
+   $ spack -e myenv add perl
+   $ spack -e myenv concretize
+   $ spack -e myenv find
+   ==> In environment myenv
+   ==> Root specs
+   perl  python
+
+   ==> 0 installed packages
+
+
+   $ spack -e included_env find
+   ==> In environment included_env
+   ==> No root specs
+   ==> Included specs
+   python
+
+   ==> 0 installed packages
+
+It isn't until you run the ``spack concretize`` command that the combined
+environment will get the updated information from the reconcretized base environmennt.
+
+.. code-block:: console
+
+   $ spack -e included_env concretize
+   $ spack -e included_env find
+   ==> In environment included_env
+   ==> No root specs
+   ==> Included specs
+   perl  python
+
+   ==> 0 installed packages
+
 .. _environment-configuration:
 
 ------------------------
@@ -811,6 +930,7 @@ For example, the following environment has three root packages:
 This allows for a much-needed reduction in redundancy between packages
 and constraints.
 
+
 ----------------
 Filesystem Views
 ----------------
@@ -1044,7 +1164,7 @@ other targets to depend on the environment installation.
 
 A typical workflow is as follows:
 
-.. code:: console
+.. code-block:: console
 
    spack env create -d .
    spack -e . add perl
@@ -1137,7 +1257,7 @@ its dependencies. This can be useful when certain flags should only apply to
 dependencies. Below we show a use case where a spec is installed with verbose
 output (``spack install --verbose``) while its dependencies are installed silently:
 
-.. code:: console
+.. code-block:: console
 
    $ spack env depfile -o Makefile
 
@@ -1159,7 +1279,7 @@ This can be accomplished through the generated ``[<prefix>/]SPACK_PACKAGE_IDS``
 variable. Assuming we have an active and concrete environment, we generate the
 associated ``Makefile`` with a prefix ``example``:
 
-.. code:: console
+.. code-block:: console
 
    $ spack env depfile -o env.mk --make-prefix example
 

lib/spack/docs/getting_started.rst

@@ -1364,187 +1364,6 @@ This will write the private key to the file `dinosaur.priv`.
     or for help on an issue or the Spack slack.
 
 
-.. _cray-support:
-
--------------
-Spack on Cray
--------------
-
-Spack differs slightly when used on a Cray system. The architecture spec
-can differentiate between the front-end and back-end processor and operating system.
-For example, on Edison at NERSC, the back-end target processor
-is "Ivy Bridge", so you can specify to use the back-end this way:
-
-.. code-block:: console
-
-   $ spack install zlib target=ivybridge
-
-You can also use the operating system to build against the back-end:
-
-.. code-block:: console
-
-   $ spack install zlib os=CNL10
-
-Notice that the name includes both the operating system name and the major
-version number concatenated together.
-
-Alternatively, if you want to build something for the front-end,
-you can specify the front-end target processor. The processor for a login node
-on Edison is "Sandy bridge" so we specify on the command line like so:
-
-.. code-block:: console
-
-   $ spack install zlib target=sandybridge
-
-And the front-end operating system is:
-
-.. code-block:: console
-
-   $ spack install zlib os=SuSE11
-
-^^^^^^^^^^^^^^^^^^^^^^^
-Cray compiler detection
-^^^^^^^^^^^^^^^^^^^^^^^
-
-Spack can detect compilers using two methods. For the front-end, we treat
-everything the same. The difference lies in back-end compiler detection.
-Back-end compiler detection is made via the Tcl module avail command.
-Once it detects the compiler it writes the appropriate PrgEnv and compiler
-module name to compilers.yaml and sets the paths to each compiler with Cray\'s
-compiler wrapper names (i.e. cc, CC, ftn). During build time, Spack will load
-the correct PrgEnv and compiler module and will call appropriate wrapper.
-
-The compilers.yaml config file will also differ. There is a
-modules section that is filled with the compiler's Programming Environment
-and module name. On other systems, this field is empty []:
-
-.. code-block:: yaml
-
-   - compiler:
-       modules:
-         - PrgEnv-intel
-         - intel/15.0.109
-
-As mentioned earlier, the compiler paths will look different on a Cray system.
-Since most compilers are invoked using cc, CC and ftn, the paths for each
-compiler are replaced with their respective Cray compiler wrapper names:
-
-.. code-block:: yaml
-
-     paths:
-       cc: cc
-       cxx: CC
-       f77: ftn
-       fc: ftn
-
-As opposed to an explicit path to the compiler executable. This allows Spack
-to call the Cray compiler wrappers during build time.
-
-For more on compiler configuration, check out :ref:`compiler-config`.
-
-Spack sets the default Cray link type to dynamic, to better match other
-other platforms. Individual packages can enable static linking (which is the
-default outside of Spack on cray systems) using the ``-static`` flag.
-
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Setting defaults and using Cray modules
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-If you want to use default compilers for each PrgEnv and also be able
-to load cray external modules, you will need to set up a ``packages.yaml``.
-
-Here's an example of an external configuration for cray modules:
-
-.. code-block:: yaml
-
-   packages:
-     mpich:
-       externals:
-       - spec: "mpich@7.3.1%gcc@5.2.0 arch=cray_xc-haswell-CNL10"
-         modules:
-         - cray-mpich
-       - spec: "mpich@7.3.1%intel@16.0.0.109 arch=cray_xc-haswell-CNL10"
-         modules:
-         - cray-mpich
-     all:
-       providers:
-         mpi: [mpich]
-
-This tells Spack that for whatever package that depends on mpi, load the
-cray-mpich module into the environment. You can then be able to use whatever
-environment variables, libraries, etc, that are brought into the environment
-via module load.
-
-.. note::
-
-    For Cray-provided packages, it is best to use ``modules:`` instead of ``prefix:``
-    in ``packages.yaml``, because the Cray Programming Environment heavily relies on
-    modules (e.g., loading the ``cray-mpich`` module adds MPI libraries to the
-    compiler wrapper link line).
-
-You can set the default compiler that Spack can use for each compiler type.
-If you want to use the Cray defaults, then set them under ``all:`` in packages.yaml.
-In the compiler field, set the compiler specs in your order of preference.
-Whenever you build with that compiler type, Spack will concretize to that version.
-
-Here is an example of a full packages.yaml used at NERSC
-
-.. code-block:: yaml
-
-   packages:
-     mpich:
-       externals:
-       - spec: "mpich@7.3.1%gcc@5.2.0 arch=cray_xc-CNL10-ivybridge"
-         modules:
-         - cray-mpich
-       - spec: "mpich@7.3.1%intel@16.0.0.109 arch=cray_xc-SuSE11-ivybridge"
-         modules:
-         - cray-mpich
-       buildable: False
-     netcdf:
-       externals:
-       - spec: "netcdf@4.3.3.1%gcc@5.2.0 arch=cray_xc-CNL10-ivybridge"
-         modules:
-         - cray-netcdf
-       - spec: "netcdf@4.3.3.1%intel@16.0.0.109 arch=cray_xc-CNL10-ivybridge"
-         modules:
-         - cray-netcdf
-       buildable: False
-     hdf5:
-       externals:
-       - spec: "hdf5@1.8.14%gcc@5.2.0 arch=cray_xc-CNL10-ivybridge"
-         modules:
-         - cray-hdf5
-       - spec: "hdf5@1.8.14%intel@16.0.0.109 arch=cray_xc-CNL10-ivybridge"
-         modules:
-         - cray-hdf5
-       buildable: False
-     all:
-       compiler: [gcc@5.2.0, intel@16.0.0.109]
-       providers:
-         mpi: [mpich]
-
-Here we tell spack that whenever we want to build with gcc use version 5.2.0 or
-if we want to build with intel compilers, use version 16.0.0.109. We add a spec
-for each compiler type for each cray modules. This ensures that for each
-compiler on our system we can use that external module.
-
-For more on external packages check out the section :ref:`sec-external-packages`.
-
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Using Linux containers on Cray machines
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Spack uses environment variables particular to the Cray programming
-environment to determine which systems are Cray platforms. These
-environment variables may be propagated into containers that are not
-using the Cray programming environment.
-
-To ensure that Spack does not autodetect the Cray programming
-environment, unset the environment variable ``MODULEPATH``. This
-will cause Spack to treat a linux container on a Cray system as a base
-linux distro.
-
 .. _windows_support:
 
 ----------------

lib/spack/docs/packaging_guide.rst

@@ -2344,6 +2344,27 @@ you set ``parallel`` to ``False`` at the package level, then each call
 to ``make()`` will be sequential by default, but packagers can call
 ``make(parallel=True)`` to override it.
 
+Note that the ``--jobs`` option works out of the box for all standard
+build systems. If you are using a non-standard build system instead, you
+can use the variable ``make_jobs`` to extract the number of jobs specified
+by the ``--jobs`` option:
+
+.. code-block:: python
+   :emphasize-lines: 7, 11
+   :linenos:
+ 
+   class Xios(Package):
+      ...
+      def install(self, spec, prefix):
+         ...
+         options = [
+            ...
+            '--jobs', str(make_jobs),
+        ]
+        ...
+        make_xios = Executable("./make_xios")
+        make_xios(*options)
+
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Install-level build parallelism
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -5173,12 +5194,6 @@ installed executable. The check is implemented as follows:
                 reframe = Executable(self.prefix.bin.reframe)
                 reframe("-l")
 
-.. warning::
-
-    The API for adding tests is not yet considered stable and may change
-    in future releases.
-
-
 """"""""""""""""""""""""""""""""
 Checking build-time test results
 """"""""""""""""""""""""""""""""
@@ -5216,38 +5231,42 @@ be left in the build stage directory as illustrated below:
 Stand-alone tests
 ^^^^^^^^^^^^^^^^^
 
-While build-time tests are integrated with the build process, stand-alone
+While build-time tests are integrated with the installation process, stand-alone
 tests are expected to run days, weeks, even months after the software is
 installed. The goal is to provide a mechanism for gaining confidence that
 packages work as installed **and** *continue* to work as the underlying
 software evolves. Packages can add and inherit stand-alone tests. The
-`spack test`` command is used to manage stand-alone testing.
+``spack test`` command is used for stand-alone testing.
 
-.. note::
+.. admonition:: Stand-alone test methods should complete within a few minutes.
 
     Execution speed is important since these tests are intended to quickly
-    assess whether installed specs work on the system. Consequently, they
-    should run relatively quickly -- as in on the order of at most a few
-    minutes -- while ideally executing all, or at least key aspects of the
-    installed software.
+    assess whether installed specs work on the system. Spack cannot spare
+    resources for more extensive testing of packages included in CI stacks.
 
-.. note::
-
-    Failing stand-alone tests indicate problems with the installation and,
-    therefore, there is no reason to proceed with more resource-intensive
-    tests until those have been investigated.
-
-    Passing stand-alone tests indicate that more thorough testing, such
-    as running extensive unit or regression tests, or tests that run at
-    scale can proceed without wasting resources on a problematic installation.
+    Consequently, stand-alone tests should run relatively quickly -- as in
+    on the order of at most a few minutes -- while testing at least key aspects
+    of the installed software. Save more extensive testing for other tools.
 
 Tests are defined in the package using methods with names beginning ``test_``.
 This allows Spack to support multiple independent checks, or parts. Files
 needed for testing, such as source, data, and expected outputs, may be saved
 from the build and or stored with the package in the repository. Regardless
 of origin, these files are automatically copied to the spec's test stage
-directory prior to execution of the test method(s). Spack also provides some
-helper functions to facilitate processing.
+directory prior to execution of the test method(s). Spack also provides helper
+functions to facilitate common processing.
+
+.. tip::
+
+    **The status of stand-alone tests can be used to guide follow-up testing efforts.**
+
+    Passing stand-alone tests justify performing more thorough testing, such
+    as running extensive unit or regression tests or tests that run at scale,
+    when available. These tests are outside of the scope of Spack packaging.
+
+    Failing stand-alone tests indicate problems with the installation and,
+    therefore, no reason to proceed with more resource-intensive tests until
+    the failures have been investigated.
 
 .. _configure-test-stage:
 
@@ -5255,30 +5274,26 @@ helper functions to facilitate processing.
 Configuring the test stage directory
 """"""""""""""""""""""""""""""""""""
 
-Stand-alone tests utilize a test stage directory for building, running,
-and tracking results in the same way Spack uses a build stage directory.
-The default test stage root directory, ``~/.spack/test``, is defined in
-:ref:`etc/spack/defaults/config.yaml <config-yaml>`. This location is
-customizable by adding or changing the ``test_stage`` path in the high-level
-``config`` of the appropriate ``config.yaml`` file such that:
+Stand-alone tests utilize a test stage directory to build, run, and track
+tests in the same way Spack uses a build stage directory to install software.
+The default test stage root directory, ``$HOME/.spack/test``, is defined in
+:ref:`config.yaml <config-yaml>`. This location is customizable by adding or
+changing the ``test_stage`` path such that:
 
 .. code-block:: yaml
 
    config:
      test_stage: /path/to/test/stage
 
-Packages can use the ``self.test_suite.stage`` property to access this setting.
-Other package properties that provide access to spec-specific subdirectories
-and files are described in :ref:`accessing staged files <accessing-files>`.
+Packages can use the ``self.test_suite.stage`` property to access the path.
 
-.. note::
+.. admonition:: Each spec being tested has its own test stage directory.
 
-   The test stage path is the root directory for the **entire suite**.
-   In other words, it is the root directory for **all specs** being
-   tested by the ``spack test run`` command. Each spec gets its own
-   stage subdirectory. Use ``self.test_suite.test_dir_for_spec(self.spec)``
-   to access the spec-specific test stage directory.
+   The ``config:test_stage`` option is the path to the root of a
+   **test suite**'s stage directories.
 
+   Other package properties that provide paths to spec-specific subdirectories
+   and files are described in :ref:`accessing-files`.
 
 .. _adding-standalone-tests:
 
@@ -5291,61 +5306,144 @@ Test recipes are defined in the package using methods with names beginning
 Each method has access to the information Spack tracks on the package, such
 as options, compilers, and dependencies, supporting the customization of tests
 to the build. Standard python ``assert`` statements and other error reporting
-mechanisms are available. Such exceptions are automatically caught and reported
+mechanisms can be used. These exceptions are automatically caught and reported
 as test failures.
 
-Each test method is an implicit test part named by the method and whose
-purpose is the method's docstring. Providing a purpose gives context for
-aiding debugging. A test method may contain embedded test parts. Spack
-outputs the test name and purpose prior to running each test method and
-any embedded test parts. For example, ``MyPackage`` below provides two basic
-examples of installation tests: ``test_always_fails`` and ``test_example``.
-As the name indicates, the first always fails. The second simply runs the
-installed example.
+Each test method is an *implicit test part* named by the method. Its purpose
+is the method's docstring. Providing a meaningful purpose for the test gives
+context that can aid debugging. Spack outputs both the name and purpose at the
+start of test execution so it's also important that the docstring/purpose be
+brief.
+
+.. tip::
+
+    We recommend naming test methods so it is clear *what* is being tested.
+    For example, if a test method is building and or running an executable
+    called ``example``, then call the method ``test_example``. This, together
+    with a similarly meaningful test purpose, will aid test comprehension,
+    debugging, and maintainability.
+
+Stand-alone tests run in an environment that provides access to information
+on the installed software, such as build options, dependencies, and compilers.
+Build options and dependencies are accessed using the same spec checks used
+by build recipes. Examples of checking :ref:`variant settings <variants>` and
+:ref:`spec constraints <testing-specs>` can be found at the provided links.
+
+.. admonition:: Spack automatically sets up the test stage directory and environment.
+
+    Spack automatically creates the test stage directory and copies
+    relevant files *prior to* running tests. It can also ensure build
+    dependencies are available **if** necessary.
+
+    The path to the test stage is configurable (see :ref:`configure-test-stage`).
+
+    Files that Spack knows to copy are those saved from the build (see
+    :ref:`cache_extra_test_sources`) and those added to the package repository
+    (see :ref:`cache_custom_files`).
+
+    Spack will use the value of the ``test_requires_compiler`` property to
+    determine whether it needs to also set up build dependencies (see
+    :ref:`test-build-tests`).
+
+The ``MyPackage`` package below provides two basic test examples: 
+``test_example`` and ``test_example2``.  The first runs the installed
+``example`` and ensures its output contains an expected string. The second
+runs ``example2`` without checking output so is only concerned with confirming
+the executable runs successfully. If the installed spec is not expected to have
+``example2``, then the check at the top of the method will raise a special
+``SkipTest`` exception, which is captured to facilitate reporting skipped test
+parts to tools like CDash.
 
 .. code-block:: python
 
    class MyPackage(Package):
        ...
 
-       def test_always_fails(self):
-           """use assert to always fail"""
-           assert False
-
        def test_example(self):
-           """run installed example"""
+           """ensure installed example works"""
+           expected = "Done."
            example = which(self.prefix.bin.example)
-           example()
+
+           # Capture stdout and stderr from running the Executable
+           # and check that the expected output was produced.
+           out = example(output=str.split, error=str.split)
+           assert expected in out, f"Expected '{expected}' in the output"
+
+       def test_example2(self):
+           """run installed example2"""
+           if self.spec.satisfies("@:1.0"):
+               # Raise SkipTest to ensure flagging the test as skipped for
+               # test reporting purposes.
+               raise SkipTest("Test is only available for v1.1 on")
+
+           example2 = which(self.prefix.bin.example2)
+           example2()
 
 Output showing the identification of each test part after running the tests
 is illustrated below.
 
 .. code-block:: console
 
-   $ spack test run --alias mypackage mypackage@1.0
+   $ spack test run --alias mypackage mypackage@2.0
    ==> Spack test mypackage
    ...
    $ spack test results -l mypackage
    ==> Results for test suite 'mypackage':
    ...
-   ==> [2023-03-10-16:03:56.625204] test: test_always_fails: use assert to always fail
+   ==> [2024-03-10-16:03:56.625439] test: test_example: ensure installed example works
    ...
-   FAILED
-   ==> [2023-03-10-16:03:56.625439] test: test_example: run installed example
+   PASSED: MyPackage::test_example
+   ==> [2024-03-10-16:03:56.625439] test: test_example2: run installed example2
    ...
-   PASSED
+   PASSED: MyPackage::test_example2
 
+.. admonition:: Do NOT implement tests that must run in the installation prefix.
 
-.. note::
+   Use of the package spec's installation prefix for building and running
+   tests is **strongly discouraged**. Doing so causes permission errors for
+   shared spack instances *and* facilities that install the software in
+   read-only file systems or directories.
 
-   If ``MyPackage`` were a recipe for a library, the tests should build
-   an example or test program that is then executed.
+   Instead, start these test methods by explicitly copying the needed files
+   from the installation prefix to the test stage directory. Note the test
+   stage directory is the current directory when the test is executed with
+   the ``spack test run`` command.
 
-A test method can include test parts using the ``test_part`` context manager.
-Each part is treated as an independent check to allow subsequent test parts
-to execute even after a test part fails.
+.. admonition:: Test methods for library packages should build test executables.
 
-.. _test-part:
+   Stand-alone tests for library packages *should* build test executables
+   that utilize the *installed* library. Doing so ensures the tests follow
+   a similar build process that users of the library would follow.
+
+   For more information on how to do this, see :ref:`test-build-tests`.
+
+.. tip::
+
+   If you want to see more examples from packages with stand-alone tests, run
+   ``spack pkg grep "def\stest" | sed "s/\/package.py.*//g" | sort -u``
+   from the command line to get a list of the packages.
+
+.. _adding-standalone-test-parts:
+
+"""""""""""""""""""""""""""""
+Adding stand-alone test parts
+"""""""""""""""""""""""""""""
+
+Sometimes dependencies between steps of a test lend themselves to being
+broken into parts. Tracking the pass/fail status of each part may aid
+debugging. Spack provides a ``test_part`` context manager for use within
+test methods.
+
+Each test part is independently run, tracked, and reported. Test parts are
+executed in the order they appear. If one fails, subsequent test parts are
+still performed even if they would also fail. This allows tools like CDash
+to track and report the status of test parts across runs. The pass/fail status
+of the enclosing test is derived from the statuses of the embedded test parts.
+
+.. admonition:: Test method and test part names **must** be unique.
+
+   Test results reporting requires that test methods and embedded test parts
+   within a package have unique names.
 
 The signature for ``test_part`` is:
 
@@ -5367,40 +5465,68 @@ where each argument has the following meaning:
 * ``work_dir`` is the path to the directory in which the test will run.
 
   The default of ``None``, or ``"."``, corresponds to the the spec's test
-  stage (i.e., ``self.test_suite.test_dir_for_spec(self.spec)``.
+  stage (i.e., ``self.test_suite.test_dir_for_spec(self.spec)``).
 
-.. admonition:: Tests should **not** run under the installation directory.
+.. admonition:: Start test part names with the name of the enclosing test.
 
-   Use of the package spec's installation directory for building and running
-   tests is **strongly** discouraged. Doing so causes permission errors for
-   shared spack instances *and* facilities that install the software in
-   read-only file systems or directories.
+   We **highly recommend** starting the names of test parts with the name
+   of the enclosing test. Doing so helps with the comprehension, readability
+   and debugging of test results.
 
-Suppose ``MyPackage`` actually installs two examples we want to use for tests.
-These checks can be implemented as separate checks or, as illustrated below,
-embedded test parts.
+Suppose ``MyPackage`` installs multiple executables that need to run in a
+specific order since the outputs from one are inputs of others. Further suppose
+we want to add an integration test that runs the executables in order. We can
+accomplish this goal by implementing a stand-alone test method consisting of
+test parts for each executable as follows:
 
 .. code-block:: python
 
    class MyPackage(Package):
        ...
 
-       def test_example(self):
-           """run installed examples"""
-           for example in ["ex1", "ex2"]:
-               with test_part(
-                   self,
-                   f"test_example_{example}",
-                   purpose=f"run installed {example}",
-                ):
-                    exe = which(join_path(self.prefix.bin, example))
-                    exe()
+       def test_series(self):
+           """run setup, perform, and report"""
 
-In this case, there will be an implicit test part for ``test_example``
-and separate sub-parts for ``ex1`` and ``ex2``. The second sub-part
-will be executed regardless of whether the first passes. The test
-log for a run where the first executable fails and the second passes
-is illustrated below.
+           with test_part(self, "test_series_setup", purpose="setup operation"):
+                exe = which(self.prefix.bin.setup))
+                exe()
+
+           with test_part(self, "test_series_run", purpose="perform operation"):
+                exe = which(self.prefix.bin.run))
+                exe()
+
+           with test_part(self, "test_series_report", purpose="generate report"):
+                exe = which(self.prefix.bin.report))
+                exe()
+
+The result is ``test_series`` runs the following executable in order: ``setup``,
+``run``, and ``report``. In this case no options are passed to any of the
+executables and no outputs from running them are checked. Consequently, the
+implementation could be simplified with a for-loop as follows:
+
+.. code-block:: python
+
+   class MyPackage(Package):
+       ...
+
+       def test_series(self):
+           """execute series setup, run, and report"""
+
+           for exe, reason in [
+               ("setup", "setup operation"),
+               ("run", "perform operation"),
+               ("report", "generate report")
+           ]:
+               with test_part(self, f"test_series_{exe}", purpose=reason):
+                   exe = which(self.prefix.bin.join(exe))
+                   exe()
+
+In both cases, since we're using a context manager, each test part in
+``test_series`` will execute regardless of the status of the other test
+parts.
+
+Now let's look at the output from running the stand-alone tests where
+the second test part, ``test_series_run``, fails.
 
 .. code-block:: console
 
@@ -5410,50 +5536,68 @@ is illustrated below.
    $ spack test results -l mypackage
    ==> Results for test suite 'mypackage':
    ...
-   ==> [2023-03-10-16:03:56.625204] test: test_example: run installed examples
-   ==> [2023-03-10-16:03:56.625439] test: test_example_ex1: run installed ex1
+   ==> [2024-03-10-16:03:56.625204] test: test_series: execute series setup, run, and report
+   ==> [2024-03-10-16:03:56.625439] test: test_series_setup: setup operation
    ...
-   FAILED
-   ==> [2023-03-10-16:03:56.625555] test: test_example_ex2: run installed ex2
+   PASSED: MyPackage::test_series_setup
+   ==> [2024-03-10-16:03:56.625555] test: test_series_run: perform operation
    ...
-   PASSED
+   FAILED: MyPackage::test_series_run
+   ==> [2024-03-10-16:03:57.003456] test: test_series_report: generate report
+   ...
+   FAILED: MyPackage::test_series_report
+   FAILED: MyPackage::test_series
    ...
 
-.. warning::
+Since test parts depended on the success of previous parts, we see that the
+failure of one results in the failure of subsequent checks and the overall
+result of the test method, ``test_series``, is failure.
 
-   Test results reporting requires that each test method and embedded
-   test part for a package have a unique name.
+.. tip::
 
-Stand-alone tests run in an environment that provides access to information
-Spack has on how the software was built, such as build options, dependencies,
-and compilers. Build options and dependencies are accessed with the normal
-spec checks. Examples of checking :ref:`variant settings <variants>` and
-:ref:`spec constraints <testing-specs>` can be found at the provided links.
-Accessing compilers in stand-alone tests that are used by the build requires
-setting a package property as described :ref:`below <test-compilation>`.
+   If you want to see more examples from packages using ``test_part``, run
+   ``spack pkg grep "test_part(" | sed "s/\/package.py.*//g" | sort -u``
+   from the command line to get a list of the packages.
 
+.. _test-build-tests:
 
-.. _test-compilation:
+"""""""""""""""""""""""""""""""""""""
+Building and running test executables
+"""""""""""""""""""""""""""""""""""""
 
-"""""""""""""""""""""""""
-Enabling test compilation
-"""""""""""""""""""""""""
+.. admonition:: Re-use build-time sources and (small) input data sets when possible.
 
-If you want to build and run binaries in tests, then you'll need to tell
-Spack to load the package's compiler configuration. This is accomplished
-by setting the package's ``test_requires_compiler`` property to ``True``.
+    We **highly recommend** re-using build-time test sources and pared down
+    input files for testing installed software. These files are easier
+    to keep synchronized with software capabilities when they reside
+    within the software's repository. More information on saving files from
+    the installation process can be found at :ref:`cache_extra_test_sources`.
 
-Setting the property to ``True`` ensures access to the compiler through
-canonical environment variables (e.g., ``CC``, ``CXX``, ``FC``, ``F77``).
-It also gives access to build dependencies like ``cmake`` through their
-``spec objects`` (e.g., ``self.spec["cmake"].prefix.bin.cmake``).
+    If that is not possible, you can add test-related files to the package
+    repository (see :ref:`cache_custom_files`). It will be important to
+    remember to maintain them so they work across listed or supported versions
+    of the package.
 
-.. note::
+Packages that build libraries are good examples of cases where you'll want
+to build test executables from the installed software before running them.
+Doing so requires you to let Spack know it needs to load the package's
+compiler configuration. This is accomplished by setting the package's
+``test_requires_compiler`` property to ``True``.
 
-   The ``test_requires_compiler`` property should be added at the top of
-   the package near other attributes, such as the ``homepage`` and ``url``.
+.. admonition:: ``test_requires_compiler = True`` is required to build test executables.
 
-Below illustrates using this feature to compile an example.
+   Setting the property to ``True`` ensures access to the compiler through
+   canonical environment variables (e.g., ``CC``, ``CXX``, ``FC``, ``F77``).
+   It also gives access to build dependencies like ``cmake`` through their
+   ``spec objects`` (e.g., ``self.spec["cmake"].prefix.bin.cmake`` for the
+   path or ``self.spec["cmake"].command`` for the ``Executable`` instance).
+
+   Be sure to add the property at the top of the package class under other
+   properties like the ``homepage``.
+
+The example below, which ignores how ``cxx-example.cpp`` is acquired,
+illustrates the basic process of compiling a test executable using the
+installed library before running it.
 
 .. code-block:: python
 
@@ -5477,28 +5621,22 @@ Below illustrates using this feature to compile an example.
            cxx_example = which(exe)
            cxx_example()
 
+Typically the files used to build and or run test executables are either
+cached from the installation (see :ref:`cache_extra_test_sources`) or added
+to the package repository (see :ref:`cache_custom_files`). There is nothing
+preventing the use of both.
 
 .. _cache_extra_test_sources:
 
-"""""""""""""""""""""""
-Saving build-time files
-"""""""""""""""""""""""
+""""""""""""""""""""""""""""""""""""
+Saving build- and install-time files
+""""""""""""""""""""""""""""""""""""
 
-.. note::
-
-    We highly recommend re-using build-time test sources and pared down
-    input files for testing installed software. These files are easier
-    to keep synchronized with software capabilities since they reside
-    within the software's repository.
-
-    If that is not possible, you can add test-related files to the package
-    repository (see :ref:`adding custom files <cache_custom_files>`). It
-    will be important to maintain them so they work across listed or supported
-    versions of the package.
-
-You can use the ``cache_extra_test_sources`` helper to copy directories
-and or files from the source build stage directory to the package's
-installation directory.
+You can use the ``cache_extra_test_sources`` helper routine to copy
+directories and or files from the source build stage directory to the
+package's installation directory. Spack will automatically copy these
+files for you when it sets up the test stage directory and before it
+begins running the tests.
 
 The signature for ``cache_extra_test_sources`` is:
 
@@ -5513,46 +5651,69 @@ where each argument has the following meaning:
 * ``srcs`` is a string *or* a list of strings corresponding to the
   paths of subdirectories and or files needed for stand-alone testing.
 
-The paths must be relative to the staged source directory. Contents of
-subdirectories and files are copied to a special test cache subdirectory
-of the installation prefix. They are automatically copied to the appropriate
-relative paths under the test stage directory prior to executing stand-alone
-tests.
+.. warning::
 
-For example, a package method for copying everything in the ``tests``
-subdirectory plus the ``foo.c`` and ``bar.c`` files from ``examples``
-and using ``foo.c`` in a test method is illustrated below.
+   Paths provided in the ``srcs`` argument **must be relative** to the
+   staged source directory. They will be copied to the equivalent relative
+   location under the test stage directory prior to test execution.
+
+Contents of subdirectories and files are copied to a special test cache
+subdirectory of the installation prefix. They are automatically copied to
+the appropriate relative paths under the test stage directory prior to
+executing stand-alone tests.
+
+.. tip:: 
+
+    *Perform test-related conversions once when copying files.*
+
+    If one or more of the copied files needs to be modified to reference
+    the installed software, it is recommended that those changes be made
+    to the cached files **once** in the post-``install`` copy method
+    **after** the call to ``cache_extra_test_sources``. This will reduce
+    the amount of unnecessary work in the test method **and** avoid problems
+    running stand-alone tests in shared instances and facility deployments.
+
+    The ``filter_file`` function can be quite useful for such changes
+    (see :ref:`file-filtering`).
+
+Below is a basic example of a test that relies on files from the installation.
+This package method re-uses the contents of the ``examples`` subdirectory,
+which is assumed to have all of the files implemented to allow ``make`` to
+compile and link ``foo.c`` and ``bar.c`` against the package's installed
+library.
 
 .. code-block:: python
 
-   class MyLibPackage(Package):
+   class MyLibPackage(MakefilePackage):
        ...
 
        @run_after("install")
        def copy_test_files(self):
-           srcs = ["tests",
-                   join_path("examples", "foo.c"),
-                   join_path("examples", "bar.c")]
-           cache_extra_test_sources(self, srcs)
+           cache_extra_test_sources(self, "examples")
 
-       def test_foo(self):
-           exe = "foo"
-           src_dir = self.test_suite.current_test_cache_dir.examples
-           with working_dir(src_dir):
-               cc = which(os.environ["CC"])
-               cc(
-                   f"-L{self.prefix.lib}",
-                   f"-I{self.prefix.include}",
-                   f"{exe}.c",
-                   "-o", exe
-               )
-               foo = which(exe)
-               foo()
+       def test_example(self):
+           """build and run the examples"""
+           examples_dir = self.test_suite.current_test_cache_dir.examples
+           with working_dir(examples_dir):
+               make = which("make")
+               make()
 
-In this case, the method copies the associated files from the build
-stage, **after** the software is installed, to the package's test
-cache directory. Then ``test_foo`` builds ``foo`` using ``foo.c``
-before running the program.
+               for program in ["foo", "bar"]:
+                   with test_part(
+                       self,
+                       f"test_example_{program}",
+                       purpose=f"ensure {program} runs"
+                   ):
+                       exe = Executable(program)
+                       exe()
+
+In this case, ``copy_test_files`` copies the associated files from the
+build stage to the package's test cache directory under the installation
+prefix. Running ``spack test run`` for the package results in Spack copying
+the directory and its contents to the the test stage directory. The
+``working_dir`` context manager ensures the commands within it are executed
+from the ``examples_dir``. The test builds the software using ``make`` before
+running each executable, ``foo`` and ``bar``, as independent test parts.
 
 .. note::
 
@@ -5561,43 +5722,18 @@ before running the program.
 
    The key to copying files for stand-alone testing at build time is use
    of the ``run_after`` directive, which ensures the associated files are
-   copied **after** the provided build stage where the files **and**
-   installation prefix are available.
+   copied **after** the provided build stage (``install``) when the installation
+   prefix **and** files are available.
 
-These paths are **automatically copied** from cache to the test stage
-directory prior to the execution of any stand-alone tests. Tests access
-the files using the ``self.test_suite.current_test_cache_dir`` property.
-In our example above, test methods can use the following paths to reference
-the copy of each entry listed in ``srcs``, respectively:
+   The test method uses the path contained in the package's
+   ``self.test_suite.current_test_cache_dir`` property for the root directory
+   of the copied files. In this case, that's the ``examples`` subdirectory.
 
-* ``self.test_suite.current_test_cache_dir.tests``
-* ``join_path(self.test_suite.current_test_cache_dir.examples, "foo.c")``
-* ``join_path(self.test_suite.current_test_cache_dir.examples, "bar.c")``
-
-.. admonition:: Library packages should build stand-alone tests
-
-    Library developers will want to build the associated tests
-    against their **installed** libraries before running them.
-
-.. note::
-
-    While source and input files are generally recommended, binaries
-    **may** also be cached by the build process. Only you, as the package
-    writer or maintainer, know whether these files would be appropriate
-    for testing the installed software weeks to months later.
-
-.. note::
-
-    If one or more of the copied files needs to be modified to reference
-    the installed software, it is recommended that those changes be made
-    to the cached files **once** in the ``copy_test_sources`` method and
-    ***after** the call to ``cache_extra_test_sources()``. This will
-    reduce the amount of unnecessary work in the test method **and** avoid
-    problems testing in shared instances and facility deployments.
-
-    The ``filter_file`` function can be quite useful for such changes.
-    See :ref:`file manipulation <file-manipulation>`.
+.. tip::
 
+   If you want to see more examples from packages that cache build files, run
+   ``spack pkg grep cache_extra_test_sources | sed "s/\/package.py.*//g" | sort -u``
+   from the command line to get a list of the packages.
 
 .. _cache_custom_files:
 
@@ -5605,8 +5741,9 @@ the copy of each entry listed in ``srcs``, respectively:
 Adding custom files
 """""""""""""""""""
 
-In some cases it can be useful to have files that can be used to build or
-check the results of tests.  Examples include:
+Sometimes it is helpful or necessary to include custom files for building and
+or checking the results of tests as part of the package. Examples of the types
+of files that might be useful are:
 
 - test source files
 - test input files
@@ -5614,17 +5751,15 @@ check the results of tests.  Examples include:
 - expected test outputs
 
 While obtaining such files from the software repository is preferred (see
-:ref:`adding build-time files  <cache_extra_test_sources>`), there are
-circumstances where that is not feasible (e.g., the software is not being
-actively maintained). When test files can't be obtained from the repository
-or as a supplement to files that can, Spack supports the inclusion of
-additional files under the ``test`` subdirectory of the package in the
-Spack repository.
+:ref:`cache_extra_test_sources`), there are circumstances where doing so is not
+feasible such as when the software is not being actively maintained. When test
+files cannot be obtained from the repository or there is a need to supplement
+files that can, Spack supports the inclusion of additional files under the
+``test`` subdirectory of the package in the Spack repository.
 
-Spack **automatically copies** the contents of that directory to the
-test staging directory prior to running stand-alone tests. Test methods
-access those files using the ``self.test_suite.current_test_data_dir``
-property as shown below.
+The following example assumes a ``custom-example.c`` is saved in ``MyLibary``
+package's ``test`` subdirectory. It also assumes the program simply needs to
+be compiled and linked against the installed ``MyLibrary`` software.
 
 .. code-block:: python
 
@@ -5634,17 +5769,29 @@ property as shown below.
        test_requires_compiler = True
        ...
 
-       def test_example(self):
+       def test_custom_example(self):
            """build and run custom-example"""
-           data_dir = self.test_suite.current_test_data_dir
+           src_dir = self.test_suite.current_test_data_dir
            exe = "custom-example"
-           src = datadir.join(f"{exe}.cpp")
-           ...
-           # TODO: Build custom-example using src and exe
-           ...
-           custom_example = which(exe)
-           custom_example()
 
+           with working_dir(src_dir):
+               cc = which(os.environ["CC"])
+               cc(
+                   f"-L{self.prefix.lib}",
+                   f"-I{self.prefix.include}",
+                   f"{exe}.cpp",
+                   "-o", exe
+               )
+
+               custom_example = Executable(exe)
+               custom_example()
+
+In this case, ``spack test run`` for the package results in Spack copying
+the contents of the ``test`` subdirectory to the test stage directory path
+in ``self.test_suite.current_test_data_dir`` before calling
+``test_custom_example``. Use of the ``working_dir`` context manager
+ensures the commands to build and run the program are performed from
+within the appropriate subdirectory of the test stage.
 
 .. _expected_test_output_from_file:
 
@@ -5653,9 +5800,8 @@ Reading expected output from a file
 """""""""""""""""""""""""""""""""""
 
 The helper function ``get_escaped_text_output`` is available for packages
-to retrieve and properly format the text from a file that contains the
-expected output from running an executable that may contain special
-characters.
+to retrieve properly formatted text from a file potentially containing
+special characters.
 
 The signature for ``get_escaped_text_output`` is:
 
@@ -5665,10 +5811,13 @@ The signature for ``get_escaped_text_output`` is:
 
 where ``filename`` is the path to the file containing the expected output.
 
-The ``filename`` for a :ref:`custom file <cache_custom_files>` can be
-accessed by tests using the ``self.test_suite.current_test_data_dir``
-property. The example below illustrates how to read a file that was
-added to the package's ``test`` subdirectory.
+The path provided to ``filename`` for one of the copied custom files
+(:ref:`custom file <cache_custom_files>`) is in the path rooted at
+``self.test_suite.current_test_data_dir``.
+
+The example below shows how to reference both the custom database
+(``packages.db``) and expected output (``dump.out``) files Spack copies
+to the test stage:
 
 .. code-block:: python
 
@@ -5690,8 +5839,9 @@ added to the package's ``test`` subdirectory.
            for exp in expected:
                assert re.search(exp, out), f"Expected '{exp}' in output"
 
-If the file was instead copied from the ``tests`` subdirectory of the staged
-source code, the path would be obtained as shown below.
+If the files were instead cached from installing the software, the paths to the
+two files would be found under the ``self.test_suite.current_test_cache_dir``
+directory as shown below:
 
 .. code-block:: python
 
@@ -5699,17 +5849,24 @@ source code, the path would be obtained as shown below.
            """check example table dump"""
            test_cache_dir = self.test_suite.current_test_cache_dir
            db_filename = test_cache_dir.join("packages.db")
+           ..
+           expected = get_escaped_text_output(test_cache_dir.join("dump.out"))
+           ...
 
-Alternatively, if the file was copied to the ``share/tests`` subdirectory
-as part of the installation process, the test could access the path as
-follows:
+Alternatively, if both files had been installed by the software into the
+``share/tests`` subdirectory of the installation prefix, the paths to the
+two files would be referenced as follows:
 
 .. code-block:: python
 
        def test_example(self):
            """check example table dump"""
-           db_filename = join_path(self.prefix.share.tests, "packages.db")
-
+           db_filename = self.prefix.share.tests.join("packages.db")
+           ..
+           expected = get_escaped_text_output(
+               self.prefix.share.tests.join("dump.out")
+           )
+           ...
 
 .. _check_outputs:
 
@@ -5717,9 +5874,9 @@ follows:
 Comparing expected to actual outputs
 """"""""""""""""""""""""""""""""""""
 
-The helper function ``check_outputs`` is available for packages to ensure
-the expected outputs from running an executable are contained within the
-actual outputs.
+The ``check_outputs`` helper routine is available for packages to ensure
+multiple expected outputs from running an executable are contained within
+the actual outputs.
 
 The signature for ``check_outputs`` is:
 
@@ -5745,11 +5902,17 @@ Invoking the method is the equivalent of:
    if errors:
        raise RuntimeError("\n ".join(errors))
 
+.. tip::
+
+   If you want to see more examples from packages that use this helper, run
+   ``spack pkg grep check_outputs | sed "s/\/package.py.*//g" | sort -u``
+   from the command line to get a list of the packages.
+
 
 .. _accessing-files:
 
 """""""""""""""""""""""""""""""""""""""""
-Accessing package- and test-related files
+Finding package- and test-related files
 """""""""""""""""""""""""""""""""""""""""
 
 You may need to access files from one or more locations when writing
@@ -5758,8 +5921,7 @@ include test source files or includes them but has no way to build the
 executables using the installed headers and libraries. In these cases
 you may need to reference the files relative to one or more root directory.
 The table below lists relevant path properties and provides additional
-examples of their use.
-:ref:`Reading expected output <expected_test_output_from_file>` provides
+examples of their use. See :ref:`expected_test_output_from_file` for
 examples of accessing files saved from the software repository, package
 repository, and installation.
 
@@ -5788,7 +5950,6 @@ repository, and installation.
      - ``self.test_suite.current_test_data_dir``
      - ``join_path(self.test_suite.current_test_data_dir, "hello.f90")``
 
-
 .. _inheriting-tests:
 
 """"""""""""""""""""""""""""
@@ -5831,7 +5992,7 @@ maintainers provide additional stand-alone tests customized to the package.
 .. warning::
 
    Any package that implements a test method with the same name as an
-   inherited method overrides the inherited method. If that is not the
+   inherited method will override the inherited method. If that is not the
    goal and you are not explicitly calling and adding functionality to
    the inherited method for the test, then make sure that all test methods
    and embedded test parts have unique test names.
@@ -5996,6 +6157,8 @@ running:
 This is already part of the boilerplate for packages created with
 ``spack create``.
 
+.. _file-filtering:
+
 ^^^^^^^^^^^^^^^^^^^
 Filtering functions
 ^^^^^^^^^^^^^^^^^^^

lib/spack/docs/pipelines.rst

@@ -253,17 +253,6 @@ can easily happen if it is not updated frequently, this behavior ensures that
 spack has a way to know for certain about the status of any concrete spec on
 the remote mirror, but can slow down pipeline generation significantly.
 
-The ``--optimize`` argument is experimental and runs the generated pipeline
-document through a series of optimization passes designed to reduce the size
-of the generated file.
-
-The ``--dependencies`` is also experimental and disables what in Gitlab is
-referred to as DAG scheduling, internally using the ``dependencies`` keyword
-rather than ``needs`` to list dependency jobs.  The drawback of using this option
-is that before any job can begin, all jobs in previous stages must first
-complete.  The benefit is that Gitlab allows more dependencies to be listed
-when using ``dependencies`` instead of ``needs``.
-
 The optional ``--output-file`` argument should be an absolute path (including
 file name) to the generated pipeline, and if not given, the default is
 ``./.gitlab-ci.yml``.

lib/spack/docs/repositories.rst

@@ -476,9 +476,3 @@ implemented using Python's built-in `sys.path
 :py:mod:`spack.repo` module implements a custom `Python importer
 <https://docs.python.org/2/library/imp.html>`_.
 
-.. warning::
-
-   The mechanism for extending packages is not yet extensively tested,
-   and extending packages across repositories imposes inter-repo
-   dependencies, which may be hard to manage.  Use this feature at your
-   own risk, but let us know if you have a use case for it.

lib/spack/docs/requirements.txt

@@ -1,13 +1,13 @@
 sphinx==7.2.6
 sphinxcontrib-programoutput==0.17
-sphinx_design==0.5.0
+sphinx_design==0.6.0
 sphinx-rtd-theme==2.0.0
 python-levenshtein==0.25.1
 docutils==0.20.1
-pygments==2.17.2
-urllib3==2.2.1
-pytest==8.2.0
+pygments==2.18.0
+urllib3==2.2.2
+pytest==8.2.2
 isort==5.13.2
 black==24.4.2
-flake8==7.0.0
-mypy==1.10.0
+flake8==7.1.0
+mypy==1.10.1

lib/spack/llnl/path.py

@@ -98,3 +98,10 @@ def path_filter_caller(*args, **kwargs):
     if _func:
         return holder_func(_func)
     return holder_func
+
+
+def sanitize_win_longpath(path: str) -> str:
+    """Strip Windows extended path prefix from strings
+    Returns sanitized string.
+    no-op if extended path prefix is not present"""
+    return path.lstrip("\\\\?\\")

lib/spack/llnl/util/filesystem.py

@@ -187,12 +187,18 @@ def polite_filename(filename: str) -> str:
     return _polite_antipattern().sub("_", filename)
 
 
-def getuid():
+def getuid() -> Union[str, int]:
+    """Returns os getuid on non Windows
+    On Windows returns 0 for admin users, login string otherwise
+    This is in line with behavior from get_owner_uid which
+    always returns the login string on Windows
+    """
     if sys.platform == "win32":
         import ctypes
 
+        # If not admin, use the string name of the login as a unique ID
         if ctypes.windll.shell32.IsUserAnAdmin() == 0:
-            return 1
+            return os.getlogin()
         return 0
     else:
         return os.getuid()
@@ -213,6 +219,15 @@ def _win_rename(src, dst):
     os.replace(src, dst)
 
 
+@system_path_filter
+def msdos_escape_parens(path):
+    """MS-DOS interprets parens as grouping parameters even in a quoted string"""
+    if sys.platform == "win32":
+        return path.replace("(", "^(").replace(")", "^)")
+    else:
+        return path
+
+
 @system_path_filter
 def rename(src, dst):
     # On Windows, os.rename will fail if the destination file already exists
@@ -553,7 +568,13 @@ def exploding_archive_handler(tarball_container, stage):
 
 
 @system_path_filter(arg_slice=slice(1))
-def get_owner_uid(path, err_msg=None):
+def get_owner_uid(path, err_msg=None) -> Union[str, int]:
+    """Returns owner UID of path destination
+    On non Windows this is the value of st_uid
+    On Windows this is the login string associated with the
+     owning user.
+
+    """
     if not os.path.exists(path):
         mkdirp(path, mode=stat.S_IRWXU)
 
@@ -745,7 +766,6 @@ def copy_tree(
     src: str,
     dest: str,
     symlinks: bool = True,
-    allow_broken_symlinks: bool = sys.platform != "win32",
     ignore: Optional[Callable[[str], bool]] = None,
     _permissions: bool = False,
 ):
@@ -768,8 +788,6 @@ def copy_tree(
         src (str): the directory to copy
         dest (str): the destination directory
         symlinks (bool): whether or not to preserve symlinks
-        allow_broken_symlinks (bool): whether or not to allow broken (dangling) symlinks,
-            On Windows, setting this to True will raise an exception. Defaults to true on unix.
         ignore (typing.Callable): function indicating which files to ignore
         _permissions (bool): for internal use only
 
@@ -777,8 +795,6 @@ def copy_tree(
         IOError: if *src* does not match any files or directories
         ValueError: if *src* is a parent directory of *dest*
     """
-    if allow_broken_symlinks and sys.platform == "win32":
-        raise llnl.util.symlink.SymlinkError("Cannot allow broken symlinks on Windows!")
     if _permissions:
         tty.debug("Installing {0} to {1}".format(src, dest))
     else:
@@ -822,7 +838,7 @@ def copy_tree(
             if islink(s):
                 link_target = resolve_link_target_relative_to_the_link(s)
                 if symlinks:
-                    target = os.readlink(s)
+                    target = readlink(s)
                     if os.path.isabs(target):
 
                         def escaped_path(path):
@@ -851,16 +867,14 @@ def escaped_path(path):
                 copy_mode(s, d)
 
     for target, d, s in links:
-        symlink(target, d, allow_broken_symlinks=allow_broken_symlinks)
+        symlink(target, d)
         if _permissions:
             set_install_permissions(d)
             copy_mode(s, d)
 
 
 @system_path_filter
-def install_tree(
-    src, dest, symlinks=True, ignore=None, allow_broken_symlinks=sys.platform != "win32"
-):
+def install_tree(src, dest, symlinks=True, ignore=None):
     """Recursively install an entire directory tree rooted at *src*.
 
     Same as :py:func:`copy_tree` with the addition of setting proper
@@ -871,21 +885,12 @@ def install_tree(
         dest (str): the destination directory
         symlinks (bool): whether or not to preserve symlinks
         ignore (typing.Callable): function indicating which files to ignore
-        allow_broken_symlinks (bool): whether or not to allow broken (dangling) symlinks,
-            On Windows, setting this to True will raise an exception.
 
     Raises:
         IOError: if *src* does not match any files or directories
         ValueError: if *src* is a parent directory of *dest*
     """
-    copy_tree(
-        src,
-        dest,
-        symlinks=symlinks,
-        allow_broken_symlinks=allow_broken_symlinks,
-        ignore=ignore,
-        _permissions=True,
-    )
+    copy_tree(src, dest, symlinks=symlinks, ignore=ignore, _permissions=True)
 
 
 @system_path_filter
@@ -2429,9 +2434,10 @@ def add_library_dependent(self, *dest):
         """
         for pth in dest:
             if os.path.isfile(pth):
-                self._additional_library_dependents.add(pathlib.Path(pth).parent)
+                new_pth = pathlib.Path(pth).parent
             else:
-                self._additional_library_dependents.add(pathlib.Path(pth))
+                new_pth = pathlib.Path(pth)
+            self._additional_library_dependents.add(new_pth)
 
     @property
     def rpaths(self):
@@ -2509,8 +2515,14 @@ def establish_link(self):
 
         # for each binary install dir in self.pkg (i.e. pkg.prefix.bin, pkg.prefix.lib)
         # install a symlink to each dependent library
-        for library, lib_dir in itertools.product(self.rpaths, self.library_dependents):
-            self._link(library, lib_dir)
+
+        # do not rpath for system libraries included in the dag
+        # we should not be modifying libraries managed by the Windows system
+        # as this will negatively impact linker behavior and can result in permission
+        # errors if those system libs are not modifiable by Spack
+        if "windows-system" not in getattr(self.pkg, "tags", []):
+            for library, lib_dir in itertools.product(self.rpaths, self.library_dependents):
+                self._link(library, lib_dir)
 
 
 @system_path_filter

lib/spack/llnl/util/symlink.py

@@ -8,100 +8,75 @@
 import subprocess
 import sys
 import tempfile
+from typing import Union
 
 from llnl.util import lang, tty
 
-from ..path import system_path_filter
+from ..path import sanitize_win_longpath, system_path_filter
 
 if sys.platform == "win32":
     from win32file import CreateHardLink
 
-is_windows = sys.platform == "win32"
 
+def _windows_symlink(
+    src: str, dst: str, target_is_directory: bool = False, *, dir_fd: Union[int, None] = None
+):
+    """On Windows with System Administrator privileges this will be a normal symbolic link via
+    os.symlink. On Windows without privledges the link will be a junction for a directory and a
+    hardlink for a file. On Windows the various link types are:
 
-def symlink(source_path: str, link_path: str, allow_broken_symlinks: bool = not is_windows):
-    """
-    Create a link.
+    Symbolic Link: A link to a file or directory on the same or different volume (drive letter) or
+    even to a remote file or directory (using UNC in its path). Need System Administrator
+    privileges to make these.
 
-    On non-Windows and Windows with System Administrator
-    privleges this will be a normal symbolic link via
-    os.symlink.
+    Hard Link: A link to a file on the same volume (drive letter) only. Every file (file's data)
+    has at least 1 hard link (file's name). But when this method creates a new hard link there will
+    be 2. Deleting all hard links effectively deletes the file. Don't need System Administrator
+    privileges.
 
-    On Windows without privledges the link will be a
-    junction for a directory and a hardlink for a file.
-    On Windows the various link types are:
-
-    Symbolic Link: A link to a file or directory on the
-    same or different volume (drive letter) or even to
-    a remote file or directory (using UNC in its path).
-    Need System Administrator privileges to make these.
-
-    Hard Link: A link to a file on the same volume (drive
-    letter) only. Every file (file's data) has at least 1
-    hard link (file's name). But when this method creates
-    a new hard link there will be 2. Deleting all hard
-    links effectively deletes the file. Don't need System
-    Administrator privileges.
-
-    Junction: A link to a directory on the same or different
-    volume (drive letter) but not to a remote directory. Don't
-    need System Administrator privileges.
-
-    Parameters:
-        source_path (str): The real file or directory that the link points to.
-            Must be absolute OR relative to the link.
-        link_path (str): The path where the link will exist.
-        allow_broken_symlinks (bool): On Linux or Mac, don't raise an exception if the source_path
-            doesn't exist. This will still raise an exception on Windows.
-    """
-    source_path = os.path.normpath(source_path)
+    Junction: A link to a directory on the same or different volume (drive letter) but not to a
+    remote directory. Don't need System Administrator privileges."""
+    source_path = os.path.normpath(src)
     win_source_path = source_path
-    link_path = os.path.normpath(link_path)
+    link_path = os.path.normpath(dst)
 
-    # Never allow broken links on Windows.
-    if sys.platform == "win32" and allow_broken_symlinks:
-        raise ValueError("allow_broken_symlinks parameter cannot be True on Windows.")
+    # Perform basic checks to make sure symlinking will succeed
+    if os.path.lexists(link_path):
+        raise AlreadyExistsError(f"Link path ({link_path}) already exists. Cannot create link.")
 
-    if not allow_broken_symlinks:
-        # Perform basic checks to make sure symlinking will succeed
-        if os.path.lexists(link_path):
-            raise AlreadyExistsError(
-                f"Link path ({link_path}) already exists. Cannot create link."
+    if not os.path.exists(source_path):
+        if os.path.isabs(source_path):
+            # An absolute source path that does not exist will result in a broken link.
+            raise SymlinkError(
+                f"Source path ({source_path}) is absolute but does not exist. Resulting "
+                f"link would be broken so not making link."
             )
-
-        if not os.path.exists(source_path):
-            if os.path.isabs(source_path) and not allow_broken_symlinks:
-                # An absolute source path that does not exist will result in a broken link.
-                raise SymlinkError(
-                    f"Source path ({source_path}) is absolute but does not exist. Resulting "
-                    f"link would be broken so not making link."
-                )
+        else:
+            # os.symlink can create a link when the given source path is relative to
+            # the link path. Emulate this behavior and check to see if the source exists
+            # relative to the link path ahead of link creation to prevent broken
+            # links from being made.
+            link_parent_dir = os.path.dirname(link_path)
+            relative_path = os.path.join(link_parent_dir, source_path)
+            if os.path.exists(relative_path):
+                # In order to work on windows, the source path needs to be modified to be
+                # relative because hardlink/junction dont resolve relative paths the same
+                # way as os.symlink. This is ignored on other operating systems.
+                win_source_path = relative_path
             else:
-                # os.symlink can create a link when the given source path is relative to
-                # the link path. Emulate this behavior and check to see if the source exists
-                # relative to the link path ahead of link creation to prevent broken
-                # links from being made.
-                link_parent_dir = os.path.dirname(link_path)
-                relative_path = os.path.join(link_parent_dir, source_path)
-                if os.path.exists(relative_path):
-                    # In order to work on windows, the source path needs to be modified to be
-                    # relative because hardlink/junction dont resolve relative paths the same
-                    # way as os.symlink. This is ignored on other operating systems.
-                    win_source_path = relative_path
-                elif not allow_broken_symlinks:
-                    raise SymlinkError(
-                        f"The source path ({source_path}) is not relative to the link path "
-                        f"({link_path}). Resulting link would be broken so not making link."
-                    )
+                raise SymlinkError(
+                    f"The source path ({source_path}) is not relative to the link path "
+                    f"({link_path}). Resulting link would be broken so not making link."
+                )
 
     # Create the symlink
-    if sys.platform == "win32" and not _windows_can_symlink():
+    if not _windows_can_symlink():
         _windows_create_link(win_source_path, link_path)
     else:
         os.symlink(source_path, link_path, target_is_directory=os.path.isdir(source_path))
 
 
-def islink(path: str) -> bool:
+def _windows_islink(path: str) -> bool:
     """Override os.islink to give correct answer for spack logic.
 
     For Non-Windows: a link can be determined with the os.path.islink method.
@@ -247,9 +222,9 @@ def _windows_create_junction(source: str, link: str):
     out, err = proc.communicate()
     tty.debug(out.decode())
     if proc.returncode != 0:
-        err = err.decode()
-        tty.error(err)
-        raise SymlinkError("Make junction command returned a non-zero return code.", err)
+        err_str = err.decode()
+        tty.error(err_str)
+        raise SymlinkError("Make junction command returned a non-zero return code.", err_str)
 
 
 def _windows_create_hard_link(path: str, link: str):
@@ -269,14 +244,14 @@ def _windows_create_hard_link(path: str, link: str):
         CreateHardLink(link, path)
 
 
-def readlink(path: str):
+def _windows_readlink(path: str, *, dir_fd=None):
     """Spack utility to override of os.readlink method to work cross platform"""
     if _windows_is_hardlink(path):
         return _windows_read_hard_link(path)
     elif _windows_is_junction(path):
         return _windows_read_junction(path)
     else:
-        return os.readlink(path)
+        return sanitize_win_longpath(os.readlink(path, dir_fd=dir_fd))
 
 
 def _windows_read_hard_link(link: str) -> str:
@@ -338,6 +313,16 @@ def resolve_link_target_relative_to_the_link(link):
     return os.path.join(link_dir, target)
 
 
+if sys.platform == "win32":
+    symlink = _windows_symlink
+    readlink = _windows_readlink
+    islink = _windows_islink
+else:
+    symlink = os.symlink
+    readlink = os.readlink
+    islink = os.path.islink
+
+
 class SymlinkError(RuntimeError):
     """Exception class for errors raised while creating symlinks,
     junctions and hard links

lib/spack/llnl/util/tty/log.py

@@ -33,8 +33,23 @@
     pass
 
 
+esc, bell, lbracket, bslash, newline = r"\x1b", r"\x07", r"\[", r"\\", r"\n"
+# Ansi Control Sequence Introducers (CSI) are a well-defined format
+# Standard ECMA-48: Control Functions for Character-Imaging I/O Devices, section 5.4
+# https://www.ecma-international.org/wp-content/uploads/ECMA-48_5th_edition_june_1991.pdf
+csi_pre = f"{esc}{lbracket}"
+csi_param, csi_inter, csi_post = r"[0-?]", r"[ -/]", r"[@-~]"
+ansi_csi = f"{csi_pre}{csi_param}*{csi_inter}*{csi_post}"
+# General ansi escape sequences have well-defined prefixes,
+#  but content and suffixes are less reliable.
+# Conservatively assume they end with either "<ESC>\" or "<BELL>",
+#  with no intervening "<ESC>"/"<BELL>" keys or newlines
+esc_pre = f"{esc}[@-_]"
+esc_content = f"[^{esc}{bell}{newline}]"
+esc_post = f"(?:{esc}{bslash}|{bell})"
+ansi_esc = f"{esc_pre}{esc_content}*{esc_post}"
 # Use this to strip escape sequences
-_escape = re.compile(r"\x1b[^m]*m|\x1b\[?1034h|\x1b\][0-9]+;[^\x07]*\x07")
+_escape = re.compile(f"{ansi_csi}|{ansi_esc}")
 
 # control characters for enabling/disabling echo
 #

lib/spack/spack/__init__.py

@@ -4,7 +4,7 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 #: PEP440 canonical <major>.<minor>.<micro>.<devN> string
-__version__ = "0.22.0.dev0"
+__version__ = "0.23.0.dev0"
 spack_version = __version__
 
 

lib/spack/spack/audit.py

@@ -254,8 +254,8 @@ def _search_duplicate_specs_in_externals(error_cls):
 
 @config_packages
 def _deprecated_preferences(error_cls):
-    """Search package preferences deprecated in v0.21 (and slated for removal in v0.22)"""
-    # TODO (v0.22): remove this audit as the attributes will not be allowed in config
+    """Search package preferences deprecated in v0.21 (and slated for removal in v0.23)"""
+    # TODO (v0.23): remove this audit as the attributes will not be allowed in config
     errors = []
     packages_yaml = spack.config.CONFIG.get_config("packages")
 
@@ -421,6 +421,10 @@ def _check_patch_urls(pkgs, error_cls):
         r"^https?://(?:patch-diff\.)?github(?:usercontent)?\.com/"
         r".+/.+/(?:commit|pull)/[a-fA-F0-9]+\.(?:patch|diff)"
     )
+    github_pull_commits_re = (
+        r"^https?://(?:patch-diff\.)?github(?:usercontent)?\.com/"
+        r".+/.+/pull/\d+/commits/[a-fA-F0-9]+\.(?:patch|diff)"
+    )
     # Only .diff URLs have stable/full hashes:
     # https://forum.gitlab.com/t/patches-with-full-index/29313
     gitlab_patch_url_re = (
@@ -436,14 +440,24 @@ def _check_patch_urls(pkgs, error_cls):
                 if not isinstance(patch, spack.patch.UrlPatch):
                     continue
 
-                if re.match(github_patch_url_re, patch.url):
+                if re.match(github_pull_commits_re, patch.url):
+                    url = re.sub(r"/pull/\d+/commits/", r"/commit/", patch.url)
+                    url = re.sub(r"^(.*)(?<!full_index=1)$", r"\1?full_index=1", url)
+                    errors.append(
+                        error_cls(
+                            f"patch URL in package {pkg_cls.name} "
+                            + "must not be a pull request commit; "
+                            + f"instead use {url}",
+                            [patch.url],
+                        )
+                    )
+                elif re.match(github_patch_url_re, patch.url):
                     full_index_arg = "?full_index=1"
                     if not patch.url.endswith(full_index_arg):
                         errors.append(
                             error_cls(
-                                "patch URL in package {0} must end with {1}".format(
-                                    pkg_cls.name, full_index_arg
-                                ),
+                                f"patch URL in package {pkg_cls.name} "
+                                + f"must end with {full_index_arg}",
                                 [patch.url],
                             )
                         )
@@ -451,9 +465,7 @@ def _check_patch_urls(pkgs, error_cls):
                     if not patch.url.endswith(".diff"):
                         errors.append(
                             error_cls(
-                                "patch URL in package {0} must end with .diff".format(
-                                    pkg_cls.name
-                                ),
+                                f"patch URL in package {pkg_cls.name} must end with .diff",
                                 [patch.url],
                             )
                         )
@@ -779,7 +791,7 @@ def check_virtual_with_variants(spec, msg):
                         return
                     error = error_cls(
                         f"{pkg_name}: {msg}",
-                        f"remove variants from '{spec}' in depends_on directive in {filename}",
+                        [f"remove variants from '{spec}' in depends_on directive in {filename}"],
                     )
                     errors.append(error)
 

lib/spack/spack/binary_distribution.py

@@ -29,6 +29,7 @@
 import llnl.util.lang
 import llnl.util.tty as tty
 from llnl.util.filesystem import BaseDirectoryVisitor, mkdirp, visit_directory_tree
+from llnl.util.symlink import readlink
 
 import spack.caches
 import spack.cmd
@@ -658,7 +659,7 @@ def get_buildfile_manifest(spec):
     #   2. paths are used as strings.
     for rel_path in visitor.symlinks:
         abs_path = os.path.join(root, rel_path)
-        link = os.readlink(abs_path)
+        link = readlink(abs_path)
         if os.path.isabs(link) and link.startswith(spack.store.STORE.layout.root):
             data["link_to_relocate"].append(rel_path)
 
@@ -2001,6 +2002,7 @@ def install_root_node(spec, unsigned=False, force=False, sha256=None):
     with spack.util.path.filter_padding():
         tty.msg('Installing "{0}" from a buildcache'.format(spec.format()))
         extract_tarball(spec, download_result, force)
+        spec.package.windows_establish_runtime_linkage()
         spack.hooks.post_install(spec, False)
         spack.store.STORE.db.add(spec, spack.store.STORE.layout)
 

lib/spack/spack/bootstrap/_common.py

@@ -213,15 +213,18 @@ def _root_spec(spec_str: str) -> str:
     Args:
         spec_str: spec to be bootstrapped. Must be without compiler and target.
     """
-    # Add a compiler requirement to the root spec.
+    # Add a compiler and platform requirement to the root spec.
     platform = str(spack.platforms.host())
+
     if platform == "darwin":
         spec_str += " %apple-clang"
+    elif platform == "windows":
+        spec_str += " %msvc"
     elif platform == "linux":
         spec_str += " %gcc"
     elif platform == "freebsd":
         spec_str += " %clang"
-
+    spec_str += f" platform={platform}"
     target = archspec.cpu.host().family
     spec_str += f" target={target}"
 

lib/spack/spack/build_environment.py

@@ -43,7 +43,7 @@
 from collections import defaultdict
 from enum import Flag, auto
 from itertools import chain
-from typing import List, Set, Tuple
+from typing import Dict, List, Set, Tuple
 
 import llnl.util.tty as tty
 from llnl.string import plural
@@ -72,6 +72,7 @@
 import spack.store
 import spack.subprocess_context
 import spack.user_environment
+import spack.util.executable
 import spack.util.path
 import spack.util.pattern
 from spack import traverse
@@ -91,7 +92,7 @@
 )
 from spack.util.executable import Executable
 from spack.util.log_parse import make_log_context, parse_log_events
-from spack.util.module_cmd import load_module, module, path_from_modules
+from spack.util.module_cmd import load_module, path_from_modules
 
 #
 # This can be set by the user to globally disable parallel builds.
@@ -190,14 +191,6 @@ def __call__(self, *args, **kwargs):
         return super().__call__(*args, **kwargs)
 
 
-def _on_cray():
-    host_platform = spack.platforms.host()
-    host_os = host_platform.operating_system("default_os")
-    on_cray = str(host_platform) == "cray"
-    using_cnl = re.match(r"cnl\d+", str(host_os))
-    return on_cray, using_cnl
-
-
 def clean_environment():
     # Stuff in here sanitizes the build environment to eliminate
     # anything the user has set that may interfere. We apply it immediately
@@ -241,17 +234,6 @@ def clean_environment():
         if varname.endswith("_ROOT") and varname != "SPACK_ROOT":
             env.unset(varname)
 
-    # On Cray "cluster" systems, unset CRAY_LD_LIBRARY_PATH to avoid
-    # interference with Spack dependencies.
-    # CNL requires these variables to be set (or at least some of them,
-    # depending on the CNL version).
-    on_cray, using_cnl = _on_cray()
-    if on_cray and not using_cnl:
-        env.unset("CRAY_LD_LIBRARY_PATH")
-        for varname in os.environ.keys():
-            if "PKGCONF" in varname:
-                env.unset(varname)
-
     # Unset the following variables because they can affect installation of
     # Autotools and CMake packages.
     build_system_vars = [
@@ -381,11 +363,7 @@ def set_compiler_environment_variables(pkg, env):
     _add_werror_handling(keep_werror, env)
 
     # Set the target parameters that the compiler will add
-    # Don't set on cray platform because the targeting module handles this
-    if spec.satisfies("platform=cray"):
-        isa_arg = ""
-    else:
-        isa_arg = spec.architecture.target.optimization_flags(compiler)
+    isa_arg = spec.architecture.target.optimization_flags(compiler)
     env.set("SPACK_TARGET_ARGS", isa_arg)
 
     # Trap spack-tracked compiler flags as appropriate.
@@ -481,10 +459,7 @@ def set_wrapper_variables(pkg, env):
 
     # Find ccache binary and hand it to build environment
     if spack.config.get("config:ccache"):
-        ccache = Executable("ccache")
-        if not ccache:
-            raise RuntimeError("No ccache binary found in PATH")
-        env.set(SPACK_CCACHE_BINARY, ccache)
+        env.set(SPACK_CCACHE_BINARY, spack.util.executable.which_string("ccache", required=True))
 
     # Gather information about various types of dependencies
     link_deps = set(pkg.spec.traverse(root=False, deptype=("link")))
@@ -730,12 +705,28 @@ def _static_to_shared_library(arch, compiler, static_lib, shared_lib=None, **kwa
     return compiler(*compiler_args, output=compiler_output)
 
 
-def get_rpath_deps(pkg):
-    """Return immediate or transitive RPATHs depending on the package."""
-    if pkg.transitive_rpaths:
-        return [d for d in pkg.spec.traverse(root=False, deptype=("link"))]
-    else:
-        return pkg.spec.dependencies(deptype="link")
+def _get_rpath_deps_from_spec(
+    spec: spack.spec.Spec, transitive_rpaths: bool
+) -> List[spack.spec.Spec]:
+    if not transitive_rpaths:
+        return spec.dependencies(deptype=dt.LINK)
+
+    by_name: Dict[str, spack.spec.Spec] = {}
+
+    for dep in spec.traverse(root=False, deptype=dt.LINK):
+        lookup = by_name.get(dep.name)
+        if lookup is None:
+            by_name[dep.name] = dep
+        elif lookup.version < dep.version:
+            by_name[dep.name] = dep
+
+    return list(by_name.values())
+
+
+def get_rpath_deps(pkg: spack.package_base.PackageBase) -> List[spack.spec.Spec]:
+    """Return immediate or transitive dependencies (depending on the package) that need to be
+    rpath'ed. If a package occurs multiple times, the newest version is kept."""
+    return _get_rpath_deps_from_spec(pkg.spec, pkg.transitive_rpaths)
 
 
 def get_rpaths(pkg):
@@ -747,7 +738,9 @@ def get_rpaths(pkg):
     # Second module is our compiler mod name. We use that to get rpaths from
     # module show output.
     if pkg.compiler.modules and len(pkg.compiler.modules) > 1:
-        rpaths.append(path_from_modules([pkg.compiler.modules[1]]))
+        mod_rpath = path_from_modules([pkg.compiler.modules[1]])
+        if mod_rpath:
+            rpaths.append(mod_rpath)
     return list(dedupe(filter_system_paths(rpaths)))
 
 
@@ -817,14 +810,6 @@ def setup_package(pkg, dirty, context: Context = Context.BUILD):
         for mod in pkg.compiler.modules:
             load_module(mod)
 
-    # kludge to handle cray mpich and libsci being automatically loaded by
-    # PrgEnv modules on cray platform. Module unload does no damage when
-    # unnecessary
-    on_cray, _ = _on_cray()
-    if on_cray and not dirty:
-        for mod in ["cray-mpich", "cray-libsci"]:
-            module("unload", mod)
-
     if target and target.module_name:
         load_module(target.module_name)
 

lib/spack/spack/build_systems/cached_cmake.py

@@ -162,7 +162,9 @@ def initconfig_compiler_entries(self):
             ld_flags = " ".join(flags["ldflags"])
             ld_format_string = "CMAKE_{0}_LINKER_FLAGS"
             # CMake has separate linker arguments for types of builds.
-            for ld_type in ["EXE", "MODULE", "SHARED", "STATIC"]:
+            # 'ldflags' should not be used with CMAKE_STATIC_LINKER_FLAGS which
+            # is used by the archiver, so don't include "STATIC" in this loop:
+            for ld_type in ["EXE", "MODULE", "SHARED"]:
                 ld_string = ld_format_string.format(ld_type)
                 entries.append(cmake_cache_string(ld_string, ld_flags))
 

lib/spack/spack/build_systems/cuda.py

@@ -110,9 +110,8 @@ def cuda_flags(arch_list):
     # From the NVIDIA install guide we know of conflicts for particular
     # platforms (linux, darwin), architectures (x86, powerpc) and compilers
     # (gcc, clang). We don't restrict %gcc and %clang conflicts to
-    # platform=linux, since they should also apply to platform=cray, and may
-    # apply to platform=darwin. We currently do not provide conflicts for
-    # platform=darwin with %apple-clang.
+    # platform=linux, since they may apply to platform=darwin. We currently
+    # do not provide conflicts for platform=darwin with %apple-clang.
 
     # Linux x86_64 compiler conflicts from here:
     # https://gist.github.com/ax3l/9489132
@@ -137,11 +136,14 @@ def cuda_flags(arch_list):
         conflicts("%gcc@11.2:", when="+cuda ^cuda@:11.5")
         conflicts("%gcc@12:", when="+cuda ^cuda@:11.8")
         conflicts("%gcc@13:", when="+cuda ^cuda@:12.3")
+        conflicts("%gcc@14:", when="+cuda ^cuda@:12.5")
         conflicts("%clang@12:", when="+cuda ^cuda@:11.4.0")
         conflicts("%clang@13:", when="+cuda ^cuda@:11.5")
         conflicts("%clang@14:", when="+cuda ^cuda@:11.7")
         conflicts("%clang@15:", when="+cuda ^cuda@:12.0")
-        conflicts("%clang@16:", when="+cuda ^cuda@:12.3")
+        conflicts("%clang@16:", when="+cuda ^cuda@:12.1")
+        conflicts("%clang@17:", when="+cuda ^cuda@:12.3")
+        conflicts("%clang@18:", when="+cuda ^cuda@:12.5")
 
         # https://gist.github.com/ax3l/9489132#gistcomment-3860114
         conflicts("%gcc@10", when="+cuda ^cuda@:11.4.0")

lib/spack/spack/build_systems/intel.py

@@ -846,6 +846,7 @@ def scalapack_libs(self):
             "^mpich@2:" in spec_root
             or "^cray-mpich" in spec_root
             or "^mvapich2" in spec_root
+            or "^mvapich" in spec_root
             or "^intel-mpi" in spec_root
             or "^intel-oneapi-mpi" in spec_root
             or "^intel-parallel-studio" in spec_root
@@ -936,32 +937,15 @@ def mpi_setup_dependent_build_environment(self, env, dependent_spec, compilers_o
             "I_MPI_ROOT": self.normalize_path("mpi"),
         }
 
-        # CAUTION - SIMILAR code in:
-        #   var/spack/repos/builtin/packages/mpich/package.py
-        #   var/spack/repos/builtin/packages/openmpi/package.py
-        #   var/spack/repos/builtin/packages/mvapich2/package.py
-        #
-        # On Cray, the regular compiler wrappers *are* the MPI wrappers.
-        if "platform=cray" in self.spec:
-            # TODO: Confirm
-            wrapper_vars.update(
-                {
-                    "MPICC": compilers_of_client["CC"],
-                    "MPICXX": compilers_of_client["CXX"],
-                    "MPIF77": compilers_of_client["F77"],
-                    "MPIF90": compilers_of_client["F90"],
-                }
-            )
-        else:
-            compiler_wrapper_commands = self.mpi_compiler_wrappers
-            wrapper_vars.update(
-                {
-                    "MPICC": compiler_wrapper_commands["MPICC"],
-                    "MPICXX": compiler_wrapper_commands["MPICXX"],
-                    "MPIF77": compiler_wrapper_commands["MPIF77"],
-                    "MPIF90": compiler_wrapper_commands["MPIF90"],
-                }
-            )
+        compiler_wrapper_commands = self.mpi_compiler_wrappers
+        wrapper_vars.update(
+            {
+                "MPICC": compiler_wrapper_commands["MPICC"],
+                "MPICXX": compiler_wrapper_commands["MPICXX"],
+                "MPIF77": compiler_wrapper_commands["MPIF77"],
+                "MPIF90": compiler_wrapper_commands["MPIF90"],
+            }
+        )
 
         # Ensure that the directory containing the compiler wrappers is in the
         # PATH. Spack packages add `prefix.bin` to their dependents' paths,

lib/spack/spack/build_systems/msbuild.py

@@ -24,7 +24,6 @@ class MSBuildPackage(spack.package_base.PackageBase):
     build_system("msbuild")
     conflicts("platform=linux", when="build_system=msbuild")
     conflicts("platform=darwin", when="build_system=msbuild")
-    conflicts("platform=cray", when="build_system=msbuild")
 
 
 @spack.builder.builder("msbuild")

lib/spack/spack/build_systems/nmake.py

@@ -24,7 +24,6 @@ class NMakePackage(spack.package_base.PackageBase):
     build_system("nmake")
     conflicts("platform=linux", when="build_system=nmake")
     conflicts("platform=darwin", when="build_system=nmake")
-    conflicts("platform=cray", when="build_system=nmake")
 
 
 @spack.builder.builder("nmake")
@@ -145,7 +144,7 @@ def install(self, pkg, spec, prefix):
         opts += self.nmake_install_args()
         if self.makefile_name:
             opts.append("/F{}".format(self.makefile_name))
-        opts.append(self.define("PREFIX", prefix))
+        opts.append(self.define("PREFIX", fs.windows_sfn(prefix)))
         with fs.working_dir(self.build_directory):
             inspect.getmodule(self.pkg).nmake(
                 *opts, *self.install_targets, ignore_quotes=self.ignore_quotes

lib/spack/spack/build_systems/oneapi.py

@@ -36,9 +36,8 @@ class IntelOneApiPackage(Package):
         "target=ppc64:",
         "target=ppc64le:",
         "target=aarch64:",
-        "platform=darwin:",
-        "platform=cray:",
-        "platform=windows:",
+        "platform=darwin",
+        "platform=windows",
     ]:
         conflicts(c, msg="This package in only available for x86_64 and Linux")
 

lib/spack/spack/build_systems/python.py

@@ -120,12 +120,6 @@ def skip_modules(self) -> Iterable[str]:
         """
         return []
 
-    @property
-    def python_spec(self):
-        """Get python-venv if it exists or python otherwise."""
-        python, *_ = self.spec.dependencies("python-venv") or self.spec.dependencies("python")
-        return python
-
     def view_file_conflicts(self, view, merge_map):
         """Report all file conflicts, excepting special cases for python.
         Specifically, this does not report errors for duplicate
@@ -146,8 +140,12 @@ def view_file_conflicts(self, view, merge_map):
     def add_files_to_view(self, view, merge_map, skip_if_exists=True):
         # Patch up shebangs if the package extends Python and we put a Python interpreter in the
         # view.
-        python = self.python_spec
-        if not self.extendee_spec or python.external:
+        if not self.extendee_spec:
+            return super().add_files_to_view(view, merge_map, skip_if_exists)
+
+        python, *_ = self.spec.dependencies("python-venv") or self.spec.dependencies("python")
+
+        if python.external:
             return super().add_files_to_view(view, merge_map, skip_if_exists)
 
         # We only patch shebangs in the bin directory.
@@ -368,6 +366,12 @@ def list_url(cls) -> Optional[str]:  # type: ignore[override]
             return f"https://pypi.org/simple/{name}/"
         return None
 
+    @property
+    def python_spec(self):
+        """Get python-venv if it exists or python otherwise."""
+        python, *_ = self.spec.dependencies("python-venv") or self.spec.dependencies("python")
+        return python
+
     @property
     def headers(self) -> HeaderList:
         """Discover header files in platlib."""

lib/spack/spack/ci.py

@@ -22,6 +22,8 @@
 from urllib.parse import urlencode
 from urllib.request import HTTPHandler, Request, build_opener
 
+import ruamel.yaml
+
 import llnl.util.filesystem as fs
 import llnl.util.tty as tty
 from llnl.util.lang import memoized
@@ -44,6 +46,7 @@
 from spack import traverse
 from spack.error import SpackError
 from spack.reporters import CDash, CDashConfiguration
+from spack.reporters.cdash import SPACK_CDASH_TIMEOUT
 from spack.reporters.cdash import build_stamp as cdash_build_stamp
 
 # See https://docs.gitlab.com/ee/ci/yaml/#retry for descriptions of conditions
@@ -550,10 +553,9 @@ def generate_gitlab_ci_yaml(
     env,
     print_summary,
     output_file,
+    *,
     prune_dag=False,
     check_index_only=False,
-    run_optimizer=False,
-    use_dependencies=False,
     artifacts_root=None,
     remote_mirror_override=None,
 ):
@@ -574,12 +576,6 @@ def generate_gitlab_ci_yaml(
             this mode results in faster yaml generation time). Otherwise, also
             check each spec directly by url (useful if there is no index or it
             might be out of date).
-        run_optimizer (bool): If True, post-process the generated yaml to try
-            try to reduce the size (attempts to collect repeated configuration
-            and replace with definitions).)
-        use_dependencies (bool): If true, use "dependencies" rather than "needs"
-            ("needs" allows DAG scheduling).  Useful if gitlab instance cannot
-            be configured to handle more than a few "needs" per job.
         artifacts_root (str): Path where artifacts like logs, environment
             files (spack.yaml, spack.lock), etc should be written.  GitLab
             requires this to be within the project directory.
@@ -683,6 +679,22 @@ def generate_gitlab_ci_yaml(
             "instead.",
         )
 
+    def ensure_expected_target_path(path):
+        """Returns passed paths with all Windows path separators exchanged
+        for posix separators only if copy_only_pipeline is enabled
+
+        This is required as copy_only_pipelines are a unique scenario where
+        the generate job and child pipelines are run on different platforms.
+        To make this compatible w/ Windows, we cannot write Windows style path separators
+        that will be consumed on by the Posix copy job runner.
+
+        TODO (johnwparent): Refactor config + cli read/write to deal only in posix
+        style paths
+        """
+        if copy_only_pipeline and path:
+            path = path.replace("\\", "/")
+        return path
+
     pipeline_mirrors = spack.mirror.MirrorCollection(binary=True)
     deprecated_mirror_config = False
     buildcache_destination = None
@@ -806,7 +818,7 @@ def generate_gitlab_ci_yaml(
             if scope not in include_scopes and scope not in env_includes:
                 include_scopes.insert(0, scope)
         env_includes.extend(include_scopes)
-        env_yaml_root["spack"]["include"] = env_includes
+        env_yaml_root["spack"]["include"] = [ensure_expected_target_path(i) for i in env_includes]
 
         if "gitlab-ci" in env_yaml_root["spack"] and "ci" not in env_yaml_root["spack"]:
             env_yaml_root["spack"]["ci"] = env_yaml_root["spack"].pop("gitlab-ci")
@@ -1227,6 +1239,9 @@ def main_script_replacements(cmd):
             "SPACK_REBUILD_EVERYTHING": str(rebuild_everything),
             "SPACK_REQUIRE_SIGNING": os.environ.get("SPACK_REQUIRE_SIGNING", "False"),
         }
+        output_vars = output_object["variables"]
+        for item, val in output_vars.items():
+            output_vars[item] = ensure_expected_target_path(val)
 
         # TODO: Remove this block in Spack 0.23
         if deprecated_mirror_config and remote_mirror_override:
@@ -1251,17 +1266,6 @@ def main_script_replacements(cmd):
             with open(copy_specs_file, "w") as fd:
                 fd.write(json.dumps(buildcache_copies))
 
-        # TODO(opadron): remove this or refactor
-        if run_optimizer:
-            import spack.ci_optimization as ci_opt
-
-            output_object = ci_opt.optimizer(output_object)
-
-        # TODO(opadron): remove this or refactor
-        if use_dependencies:
-            import spack.ci_needs_workaround as cinw
-
-            output_object = cinw.needs_to_dependencies(output_object)
     else:
         # No jobs were generated
         noop_job = spack_ci_ir["jobs"]["noop"]["attributes"]
@@ -1283,7 +1287,6 @@ def main_script_replacements(cmd):
     sorted_output = {}
     for output_key, output_value in sorted(output_object.items()):
         sorted_output[output_key] = output_value
-
     if known_broken_specs_encountered:
         tty.error("This pipeline generated hashes known to be broken on develop:")
         display_broken_spec_messages(broken_specs_url, known_broken_specs_encountered)
@@ -1291,8 +1294,11 @@ def main_script_replacements(cmd):
         if not rebuild_everything:
             sys.exit(1)
 
-    with open(output_file, "w") as outf:
-        outf.write(syaml.dump(sorted_output, default_flow_style=True))
+    # Minimize yaml output size through use of anchors
+    syaml.anchorify(sorted_output)
+
+    with open(output_file, "w") as f:
+        ruamel.yaml.YAML().dump(sorted_output, f)
 
 
 def _url_encode_string(input_string):
@@ -1478,6 +1484,12 @@ def copy_test_logs_to_artifacts(test_stage, job_test_dir):
     copy_files_to_artifacts(os.path.join(test_stage, "*", "*.txt"), job_test_dir)
 
 
+def win_quote(quote_str: str) -> str:
+    if IS_WINDOWS:
+        quote_str = f'"{quote_str}"'
+    return quote_str
+
+
 def download_and_extract_artifacts(url, work_dir):
     """Look for gitlab artifacts.zip at the given url, and attempt to download
         and extract the contents into the given work_dir
@@ -1500,7 +1512,7 @@ def download_and_extract_artifacts(url, work_dir):
     request = Request(url, headers=headers)
     request.get_method = lambda: "GET"
 
-    response = opener.open(request)
+    response = opener.open(request, timeout=SPACK_CDASH_TIMEOUT)
     response_code = response.getcode()
 
     if response_code != 200:
@@ -1942,9 +1954,9 @@ def compose_command_err_handling(args):
         # but we need to handle EXEs (git, etc) ourselves
         catch_exe_failure = (
             """
-if ($LASTEXITCODE -ne 0){
-    throw "Command {} has failed"
-}
+if ($LASTEXITCODE -ne 0){{
+    throw 'Command {} has failed'
+}}
 """
             if IS_WINDOWS
             else ""
@@ -2176,13 +2188,13 @@ def __init__(self, ci_cdash):
     def args(self):
         return [
             "--cdash-upload-url",
-            self.upload_url,
+            win_quote(self.upload_url),
             "--cdash-build",
-            self.build_name,
+            win_quote(self.build_name),
             "--cdash-site",
-            self.site,
+            win_quote(self.site),
             "--cdash-buildstamp",
-            self.build_stamp,
+            win_quote(self.build_stamp),
         ]
 
     @property  # type: ignore
@@ -2248,7 +2260,7 @@ def create_buildgroup(self, opener, headers, url, group_name, group_type):
 
         request = Request(url, data=enc_data, headers=headers)
 
-        response = opener.open(request)
+        response = opener.open(request, timeout=SPACK_CDASH_TIMEOUT)
         response_code = response.getcode()
 
         if response_code not in [200, 201]:
@@ -2294,7 +2306,7 @@ def populate_buildgroup(self, job_names):
         request = Request(url, data=enc_data, headers=headers)
         request.get_method = lambda: "PUT"
 
-        response = opener.open(request)
+        response = opener.open(request, timeout=SPACK_CDASH_TIMEOUT)
         response_code = response.getcode()
 
         if response_code != 200:

lib/spack/spack/ci_needs_workaround.py

@@ -1,34 +0,0 @@
-# Copyright 2013-2024 Lawrence Livermore National Security, LLC and other
-# Spack Project Developers. See the top-level COPYRIGHT file for details.
-#
-# SPDX-License-Identifier: (Apache-2.0 OR MIT)
-import collections.abc
-
-get_job_name = lambda needs_entry: (
-    needs_entry.get("job")
-    if (isinstance(needs_entry, collections.abc.Mapping) and needs_entry.get("artifacts", True))
-    else needs_entry if isinstance(needs_entry, str) else None
-)
-
-
-def convert_job(job_entry):
-    if not isinstance(job_entry, collections.abc.Mapping):
-        return job_entry
-
-    needs = job_entry.get("needs")
-    if needs is None:
-        return job_entry
-
-    new_job = {}
-    new_job.update(job_entry)
-    del new_job["needs"]
-
-    new_job["dependencies"] = list(
-        filter((lambda x: x is not None), (get_job_name(needs_entry) for needs_entry in needs))
-    )
-
-    return new_job
-
-
-def needs_to_dependencies(yaml):
-    return dict((k, convert_job(v)) for k, v in yaml.items())

lib/spack/spack/ci_optimization.py

@@ -1,363 +0,0 @@
-# Copyright 2013-2024 Lawrence Livermore National Security, LLC and other
-# Spack Project Developers. See the top-level COPYRIGHT file for details.
-#
-# SPDX-License-Identifier: (Apache-2.0 OR MIT)
-import collections
-import collections.abc
-import copy
-import hashlib
-
-import spack.util.spack_yaml as syaml
-
-
-def sort_yaml_obj(obj):
-    if isinstance(obj, collections.abc.Mapping):
-        return syaml.syaml_dict(
-            (k, sort_yaml_obj(v)) for k, v in sorted(obj.items(), key=(lambda item: str(item[0])))
-        )
-
-    if isinstance(obj, collections.abc.Sequence) and not isinstance(obj, str):
-        return syaml.syaml_list(sort_yaml_obj(x) for x in obj)
-
-    return obj
-
-
-def matches(obj, proto):
-    """Returns True if the test object "obj" matches the prototype object
-    "proto".
-
-    If obj and proto are mappings, obj matches proto if (key in obj) and
-    (obj[key] matches proto[key]) for every key in proto.
-
-    If obj and proto are sequences, obj matches proto if they are of the same
-    length and (a matches b) for every (a,b) in zip(obj, proto).
-
-    Otherwise, obj matches proto if obj == proto.
-
-    Precondition: proto must not have any reference cycles
-    """
-    if isinstance(obj, collections.abc.Mapping):
-        if not isinstance(proto, collections.abc.Mapping):
-            return False
-
-        return all((key in obj and matches(obj[key], val)) for key, val in proto.items())
-
-    if isinstance(obj, collections.abc.Sequence) and not isinstance(obj, str):
-        if not (isinstance(proto, collections.abc.Sequence) and not isinstance(proto, str)):
-            return False
-
-        if len(obj) != len(proto):
-            return False
-
-        return all(matches(obj[index], val) for index, val in enumerate(proto))
-
-    return obj == proto
-
-
-def subkeys(obj, proto):
-    """Returns the test mapping "obj" after factoring out the items it has in
-    common with the prototype mapping "proto".
-
-    Consider a recursive merge operation, merge(a, b) on mappings a and b, that
-    returns a mapping, m, whose keys are the union of the keys of a and b, and
-    for every such key, "k", its corresponding value is:
-
-      - merge(a[key], b[key])  if a[key] and b[key] are mappings, or
-      - b[key]                 if (key in b) and not matches(a[key], b[key]),
-                               or
-      - a[key]                 otherwise
-
-
-    If obj and proto are mappings, the returned object is the smallest object,
-    "a", such that merge(a, proto) matches obj.
-
-    Otherwise, obj is returned.
-    """
-    if not (
-        isinstance(obj, collections.abc.Mapping) and isinstance(proto, collections.abc.Mapping)
-    ):
-        return obj
-
-    new_obj = {}
-    for key, value in obj.items():
-        if key not in proto:
-            new_obj[key] = value
-            continue
-
-        if matches(value, proto[key]) and matches(proto[key], value):
-            continue
-
-        if isinstance(value, collections.abc.Mapping):
-            new_obj[key] = subkeys(value, proto[key])
-            continue
-
-        new_obj[key] = value
-
-    return new_obj
-
-
-def add_extends(yaml, key):
-    """Modifies the given object "yaml" so that it includes an "extends" key
-    whose value features "key".
-
-    If "extends" is not in yaml, then yaml is modified such that
-    yaml["extends"] == key.
-
-    If yaml["extends"] is a str, then yaml is modified such that
-    yaml["extends"] == [yaml["extends"], key]
-
-    If yaml["extends"] is a list that does not include key, then key is
-    appended to the list.
-
-    Otherwise, yaml is left unchanged.
-    """
-
-    has_key = "extends" in yaml
-    extends = yaml.get("extends")
-
-    if has_key and not isinstance(extends, (str, collections.abc.Sequence)):
-        return
-
-    if extends is None:
-        yaml["extends"] = key
-        return
-
-    if isinstance(extends, str):
-        if extends != key:
-            yaml["extends"] = [extends, key]
-        return
-
-    if key not in extends:
-        extends.append(key)
-
-
-def common_subobject(yaml, sub):
-    """Factor prototype object "sub" out of the values of mapping "yaml".
-
-    Consider a modified copy of yaml, "new", where for each key, "key" in yaml:
-
-      - If yaml[key] matches sub, then new[key] = subkeys(yaml[key], sub).
-      - Otherwise, new[key] = yaml[key].
-
-    If the above match criteria is not satisfied for any such key, then (yaml,
-    None) is returned. The yaml object is returned unchanged.
-
-    Otherwise, each matching value in new is modified as in
-    add_extends(new[key], common_key), and then new[common_key] is set to sub.
-    The common_key value is chosen such that it does not match any preexisting
-    key in new. In this case, (new, common_key) is returned.
-    """
-    match_list = set(k for k, v in yaml.items() if matches(v, sub))
-
-    if not match_list:
-        return yaml, None
-
-    common_prefix = ".c"
-    common_index = 0
-
-    while True:
-        common_key = "".join((common_prefix, str(common_index)))
-        if common_key not in yaml:
-            break
-        common_index += 1
-
-    new_yaml = {}
-
-    for key, val in yaml.items():
-        new_yaml[key] = copy.deepcopy(val)
-
-        if not matches(val, sub):
-            continue
-
-        new_yaml[key] = subkeys(new_yaml[key], sub)
-        add_extends(new_yaml[key], common_key)
-
-    new_yaml[common_key] = sub
-
-    return new_yaml, common_key
-
-
-def print_delta(name, old, new, applied=None):
-    delta = new - old
-    reldelta = (1000 * delta) // old
-    reldelta = (reldelta // 10, reldelta % 10)
-
-    if applied is None:
-        applied = new <= old
-
-    print(
-        "\n".join(
-            (
-                "{0} {1}:",
-                "  before: {2: 10d}",
-                "  after : {3: 10d}",
-                "  delta : {4:+10d} ({5:=+3d}.{6}%)",
-            )
-        ).format(name, ("+" if applied else "x"), old, new, delta, reldelta[0], reldelta[1])
-    )
-
-
-def try_optimization_pass(name, yaml, optimization_pass, *args, **kwargs):
-    """Try applying an optimization pass and return information about the
-    result
-
-    "name" is a string describing the nature of the pass. If it is a non-empty
-    string, summary statistics are also printed to stdout.
-
-    "yaml" is the object to apply the pass to.
-
-    "optimization_pass" is the function implementing the pass to be applied.
-
-    "args" and "kwargs" are the additional arguments to pass to optimization
-    pass. The pass is applied as
-
-    >>> (new_yaml, *other_results) = optimization_pass(yaml, *args, **kwargs)
-
-    The pass's results are greedily rejected if it does not modify the original
-    yaml document, or if it produces a yaml document that serializes to a
-    larger string.
-
-    Returns (new_yaml, yaml, applied, other_results) if applied, or
-    (yaml, new_yaml, applied, other_results) otherwise.
-    """
-    result = optimization_pass(yaml, *args, **kwargs)
-    new_yaml, other_results = result[0], result[1:]
-
-    if new_yaml is yaml:
-        # pass was not applied
-        return (yaml, new_yaml, False, other_results)
-
-    pre_size = len(syaml.dump_config(sort_yaml_obj(yaml), default_flow_style=True))
-    post_size = len(syaml.dump_config(sort_yaml_obj(new_yaml), default_flow_style=True))
-
-    # pass makes the size worse: not applying
-    applied = post_size <= pre_size
-    if applied:
-        yaml, new_yaml = new_yaml, yaml
-
-    if name:
-        print_delta(name, pre_size, post_size, applied)
-
-    return (yaml, new_yaml, applied, other_results)
-
-
-def build_histogram(iterator, key):
-    """Builds a histogram of values given an iterable of mappings and a key.
-
-    For each mapping "m" with key "key" in iterator, the value m[key] is
-    considered.
-
-    Returns a list of tuples (hash, count, proportion, value), where
-
-      - "hash" is a sha1sum hash of the value.
-      - "count" is the number of occurences of values that hash to "hash".
-      - "proportion" is the proportion of all values considered above that
-        hash to "hash".
-      - "value" is one of the values considered above that hash to "hash".
-        Which value is chosen when multiple values hash to the same "hash" is
-        undefined.
-
-    The list is sorted in descending order by count, yielding the most
-    frequently occuring hashes first.
-    """
-    buckets = collections.defaultdict(int)
-    values = {}
-
-    num_objects = 0
-    for obj in iterator:
-        num_objects += 1
-
-        try:
-            val = obj[key]
-        except (KeyError, TypeError):
-            continue
-
-        value_hash = hashlib.sha1()
-        value_hash.update(syaml.dump_config(sort_yaml_obj(val)).encode())
-        value_hash = value_hash.hexdigest()
-
-        buckets[value_hash] += 1
-        values[value_hash] = val
-
-    return [
-        (h, buckets[h], float(buckets[h]) / num_objects, values[h])
-        for h in sorted(buckets.keys(), key=lambda k: -buckets[k])
-    ]
-
-
-def optimizer(yaml):
-    original_size = len(syaml.dump_config(sort_yaml_obj(yaml), default_flow_style=True))
-
-    # try factoring out commonly repeated portions
-    common_job = {
-        "variables": {"SPACK_COMPILER_ACTION": "NONE"},
-        "after_script": ['rm -rf "./spack"'],
-        "artifacts": {"paths": ["jobs_scratch_dir", "cdash_report"], "when": "always"},
-    }
-
-    # look for a list of tags that appear frequently
-    _, count, proportion, tags = next(iter(build_histogram(yaml.values(), "tags")), (None,) * 4)
-
-    # If a list of tags is found, and there are more than one job that uses it,
-    # *and* the jobs that do use it represent at least 70% of all jobs, then
-    # add the list to the prototype object.
-    if tags and count > 1 and proportion >= 0.70:
-        common_job["tags"] = tags
-
-    # apply common object factorization
-    yaml, other, applied, rest = try_optimization_pass(
-        "general common object factorization", yaml, common_subobject, common_job
-    )
-
-    # look for a common script, and try factoring that out
-    _, count, proportion, script = next(
-        iter(build_histogram(yaml.values(), "script")), (None,) * 4
-    )
-
-    if script and count > 1 and proportion >= 0.70:
-        yaml, other, applied, rest = try_optimization_pass(
-            "script factorization", yaml, common_subobject, {"script": script}
-        )
-
-    # look for a common before_script, and try factoring that out
-    _, count, proportion, script = next(
-        iter(build_histogram(yaml.values(), "before_script")), (None,) * 4
-    )
-
-    if script and count > 1 and proportion >= 0.70:
-        yaml, other, applied, rest = try_optimization_pass(
-            "before_script factorization", yaml, common_subobject, {"before_script": script}
-        )
-
-    # Look specifically for the SPACK_ROOT_SPEC environment variables.
-    # Try to factor them out.
-    h = build_histogram(
-        (getattr(val, "get", lambda *args: {})("variables") for val in yaml.values()),
-        "SPACK_ROOT_SPEC",
-    )
-
-    # In this case, we try to factor out *all* instances of the SPACK_ROOT_SPEC
-    # environment variable; not just the one that appears with the greatest
-    # frequency. We only require that more than 1 job uses a given instance's
-    # value, because we expect the value to be very large, and so expect even
-    # few-to-one factorizations to yield large space savings.
-    counter = 0
-    for _, count, proportion, spec in h:
-        if count <= 1:
-            continue
-
-        counter += 1
-
-        yaml, other, applied, rest = try_optimization_pass(
-            "SPACK_ROOT_SPEC factorization ({count})".format(count=counter),
-            yaml,
-            common_subobject,
-            {"variables": {"SPACK_ROOT_SPEC": spec}},
-        )
-
-    new_size = len(syaml.dump_config(sort_yaml_obj(yaml), default_flow_style=True))
-
-    print("\n")
-    print_delta("overall summary", original_size, new_size)
-    print("\n")
-    return yaml

lib/spack/spack/cmd/__init__.py

@@ -444,7 +444,7 @@ def format_list(specs):
 def filter_loaded_specs(specs):
     """Filter a list of specs returning only those that are
     currently loaded."""
-    hashes = os.environ.get(uenv.spack_loaded_hashes_var, "").split(":")
+    hashes = os.environ.get(uenv.spack_loaded_hashes_var, "").split(os.pathsep)
     return [x for x in specs if x.dag_hash() in hashes]
 
 

lib/spack/spack/cmd/buildcache.py

@@ -13,7 +13,6 @@
 import shutil
 import sys
 import tempfile
-import urllib.request
 from typing import Dict, List, Optional, Tuple, Union
 
 import llnl.util.tty as tty
@@ -54,6 +53,7 @@
 from spack.oci.oci import (
     copy_missing_layers_with_retry,
     get_manifest_and_config_with_retry,
+    list_tags,
     upload_blob_with_retry,
     upload_manifest_with_retry,
 )
@@ -856,10 +856,7 @@ def _config_from_tag(image_ref: ImageReference, tag: str) -> Optional[dict]:
 
 
 def _update_index_oci(image_ref: ImageReference, tmpdir: str, pool: MaybePool) -> None:
-    request = urllib.request.Request(url=image_ref.tags_url())
-    response = spack.oci.opener.urlopen(request)
-    spack.oci.opener.ensure_status(request, response, 200)
-    tags = json.load(response)["tags"]
+    tags = list_tags(image_ref)
 
     # Fetch all image config files in parallel
     spec_dicts = pool.starmap(

lib/spack/spack/cmd/ci.py

@@ -6,6 +6,7 @@
 import json
 import os
 import shutil
+import warnings
 from urllib.parse import urlparse, urlunparse
 
 import llnl.util.filesystem as fs
@@ -31,7 +32,6 @@
 level = "long"
 
 SPACK_COMMAND = "spack"
-MAKE_COMMAND = "make"
 INSTALL_FAIL_CODE = 1
 FAILED_CREATE_BUILDCACHE_CODE = 100
 
@@ -40,6 +40,12 @@ def deindent(desc):
     return desc.replace("    ", "")
 
 
+def unicode_escape(path: str) -> str:
+    """Returns transformed path with any unicode
+    characters replaced with their corresponding escapes"""
+    return path.encode("unicode-escape").decode("utf-8")
+
+
 def setup_parser(subparser):
     setup_parser.parser = subparser
     subparsers = subparser.add_subparsers(help="CI sub-commands")
@@ -68,7 +74,7 @@ def setup_parser(subparser):
         "--optimize",
         action="store_true",
         default=False,
-        help="(experimental) optimize the gitlab yaml file for size\n\n"
+        help="(DEPRECATED) optimize the gitlab yaml file for size\n\n"
         "run the generated document through a series of optimization passes "
         "designed to reduce the size of the generated file",
     )
@@ -76,7 +82,7 @@ def setup_parser(subparser):
         "--dependencies",
         action="store_true",
         default=False,
-        help="(experimental) disable DAG scheduling (use 'plain' dependencies)",
+        help="(DEPRECATED) disable DAG scheduling (use 'plain' dependencies)",
     )
     generate.add_argument(
         "--buildcache-destination",
@@ -195,6 +201,18 @@ def ci_generate(args):
     before invoking this command. the value must be the CDash authorization token needed to create
     a build group and register all generated jobs under it
     """
+    if args.optimize:
+        warnings.warn(
+            "The --optimize option has been deprecated, and currently has no effect. "
+            "It will be removed in Spack v0.24."
+        )
+
+    if args.dependencies:
+        warnings.warn(
+            "The --dependencies option has been deprecated, and currently has no effect. "
+            "It will be removed in Spack v0.24."
+        )
+
     env = spack.cmd.require_active_env(cmd_name="ci generate")
 
     if args.copy_to:
@@ -207,8 +225,6 @@ def ci_generate(args):
 
     output_file = args.output_file
     copy_yaml_to = args.copy_to
-    run_optimizer = args.optimize
-    use_dependencies = args.dependencies
     prune_dag = args.prune_dag
     index_only = args.index_only
     artifacts_root = args.artifacts_root
@@ -229,8 +245,6 @@ def ci_generate(args):
         output_file,
         prune_dag=prune_dag,
         check_index_only=index_only,
-        run_optimizer=run_optimizer,
-        use_dependencies=use_dependencies,
         artifacts_root=artifacts_root,
         remote_mirror_override=buildcache_destination,
     )
@@ -551,75 +565,35 @@ def ci_rebuild(args):
     # No hash match anywhere means we need to rebuild spec
 
     # Start with spack arguments
-    spack_cmd = [SPACK_COMMAND, "--color=always", "--backtrace", "--verbose"]
+    spack_cmd = [SPACK_COMMAND, "--color=always", "--backtrace", "--verbose", "install"]
 
     config = cfg.get("config")
     if not config["verify_ssl"]:
         spack_cmd.append("-k")
 
-    install_args = []
+    install_args = [f'--use-buildcache={spack_ci.win_quote("package:never,dependencies:only")}']
 
     can_verify = spack_ci.can_verify_binaries()
     verify_binaries = can_verify and spack_is_pr_pipeline is False
     if not verify_binaries:
         install_args.append("--no-check-signature")
 
-    slash_hash = "/{}".format(job_spec.dag_hash())
-
-    # Arguments when installing dependencies from cache
-    deps_install_args = install_args
+    slash_hash = spack_ci.win_quote("/" + job_spec.dag_hash())
 
     # Arguments when installing the root from sources
-    root_install_args = install_args + [
-        "--keep-stage",
-        "--only=package",
-        "--use-buildcache=package:never,dependencies:only",
-    ]
+    deps_install_args = install_args + ["--only=dependencies"]
+    root_install_args = install_args + ["--keep-stage", "--only=package"]
+
     if cdash_handler:
         # Add additional arguments to `spack install` for CDash reporting.
         root_install_args.extend(cdash_handler.args())
-    root_install_args.append(slash_hash)
-
-    # ["x", "y"] -> "'x' 'y'"
-    args_to_string = lambda args: " ".join("'{}'".format(arg) for arg in args)
 
     commands = [
         # apparently there's a race when spack bootstraps? do it up front once
-        [SPACK_COMMAND, "-e", env.path, "bootstrap", "now"],
-        [
-            SPACK_COMMAND,
-            "-e",
-            env.path,
-            "env",
-            "depfile",
-            "-o",
-            "Makefile",
-            "--use-buildcache=package:never,dependencies:only",
-            slash_hash,  # limit to spec we're building
-        ],
-        [
-            # --output-sync requires GNU make 4.x.
-            # Old make errors when you pass it a flag it doesn't recognize,
-            # but it doesn't error or warn when you set unrecognized flags in
-            # this variable.
-            "export",
-            "GNUMAKEFLAGS=--output-sync=recurse",
-        ],
-        [
-            MAKE_COMMAND,
-            "SPACK={}".format(args_to_string(spack_cmd)),
-            "SPACK_COLOR=always",
-            "SPACK_INSTALL_FLAGS={}".format(args_to_string(deps_install_args)),
-            "-j$(nproc)",
-            "install-deps/{}".format(
-                spack.environment.depfile.MakefileSpec(job_spec).safe_format(
-                    "{name}-{version}-{hash}"
-                )
-            ),
-        ],
-        spack_cmd + ["install"] + root_install_args,
+        [SPACK_COMMAND, "-e", unicode_escape(env.path), "bootstrap", "now"],
+        spack_cmd + deps_install_args + [slash_hash],
+        spack_cmd + root_install_args + [slash_hash],
     ]
-
     tty.debug("Installing {0} from source".format(job_spec.name))
     install_exit_code = spack_ci.process_command("install", commands, repro_dir)
 

lib/spack/spack/cmd/clean.py

@@ -106,7 +106,8 @@ def clean(parser, args):
 
     # Then do the cleaning falling through the cases
     if args.specs:
-        specs = spack.cmd.parse_specs(args.specs, concretize=True)
+        specs = spack.cmd.parse_specs(args.specs, concretize=False)
+        specs = list(spack.cmd.matching_spec_from_env(x) for x in specs)
         for spec in specs:
             msg = "Cleaning build stage [{0}]"
             tty.msg(msg.format(spec.short_spec))

lib/spack/spack/cmd/concretize.py

@@ -3,6 +3,9 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
+import llnl.util.tty as tty
+from llnl.string import plural
+
 import spack.cmd
 import spack.cmd.common.arguments
 import spack.environment as ev
@@ -43,5 +46,9 @@ def concretize(parser, args):
     with env.write_transaction():
         concretized_specs = env.concretize(force=args.force, tests=tests)
         if not args.quiet:
-            ev.display_specs(concretized_specs)
+            if concretized_specs:
+                tty.msg(f"Concretized {plural(len(concretized_specs), 'spec')}:")
+                ev.display_specs([concrete for _, concrete in concretized_specs])
+            else:
+                tty.msg("No new specs to concretize.")
         env.write()

lib/spack/spack/cmd/develop.py

@@ -9,6 +9,8 @@
 
 import spack.cmd
 import spack.config
+import spack.fetch_strategy
+import spack.repo
 import spack.spec
 import spack.util.path
 import spack.version
@@ -69,13 +71,15 @@ def _retrieve_develop_source(spec, abspath):
     # We construct a package class ourselves, rather than asking for
     # Spec.package, since Spec only allows this when it is concrete
     package = pkg_cls(spec)
-    if isinstance(package.stage[0].fetcher, spack.fetch_strategy.GitFetchStrategy):
-        package.stage[0].fetcher.get_full_repo = True
+    source_stage = package.stage[0]
+    if isinstance(source_stage.fetcher, spack.fetch_strategy.GitFetchStrategy):
+        source_stage.fetcher.get_full_repo = True
         # If we retrieved this version before and cached it, we may have
         # done so without cloning the full git repo; likewise, any
         # mirror might store an instance with truncated history.
-        package.stage[0].disable_mirrors()
+        source_stage.disable_mirrors()
 
+    source_stage.fetcher.set_package(package)
     package.stage.steal_source(abspath)
 
 

lib/spack/spack/cmd/edit.py

@@ -3,6 +3,7 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
+import errno
 import glob
 import os
 
@@ -11,43 +12,13 @@
 import spack.cmd
 import spack.paths
 import spack.repo
-from spack.spec import Spec
-from spack.util.editor import editor
+import spack.util.editor
 
 description = "open package files in $EDITOR"
 section = "packaging"
 level = "short"
 
 
-def edit_package(name, repo_path, namespace):
-    """Opens the requested package file in your favorite $EDITOR.
-
-    Args:
-        name (str): The name of the package
-        repo_path (str): The path to the repository containing this package
-        namespace (str): A valid namespace registered with Spack
-    """
-    # Find the location of the package
-    if repo_path:
-        repo = spack.repo.Repo(repo_path)
-    elif namespace:
-        repo = spack.repo.PATH.get_repo(namespace)
-    else:
-        repo = spack.repo.PATH
-    path = repo.filename_for_package_name(name)
-
-    spec = Spec(name)
-    if os.path.exists(path):
-        if not os.path.isfile(path):
-            tty.die("Something is wrong. '{0}' is not a file!".format(path))
-        if not os.access(path, os.R_OK):
-            tty.die("Insufficient permissions on '%s'!" % path)
-    else:
-        raise spack.repo.UnknownPackageError(spec.name)
-
-    editor(path)
-
-
 def setup_parser(subparser):
     excl_args = subparser.add_mutually_exclusive_group()
 
@@ -98,41 +69,67 @@ def setup_parser(subparser):
     excl_args.add_argument("-r", "--repo", default=None, help="path to repo to edit package in")
     excl_args.add_argument("-N", "--namespace", default=None, help="namespace of package to edit")
 
-    subparser.add_argument("package", nargs="?", default=None, help="package name")
+    subparser.add_argument("package", nargs="*", default=None, help="package name")
+
+
+def locate_package(name: str, repo: spack.repo.Repo) -> str:
+    path = repo.filename_for_package_name(name)
+
+    try:
+        with open(path, "r"):
+            return path
+    except OSError as e:
+        if e.errno == errno.ENOENT:
+            raise spack.repo.UnknownPackageError(name) from e
+        tty.die(f"Cannot edit package: {e}")
+
+
+def locate_file(name: str, path: str) -> str:
+    # convert command names to python module name
+    if path == spack.paths.command_path:
+        name = spack.cmd.python_name(name)
+
+    file_path = os.path.join(path, name)
+
+    # Try to open direct match.
+    try:
+        with open(file_path, "r"):
+            return file_path
+    except OSError as e:
+        if e.errno != errno.ENOENT:
+            tty.die(f"Cannot edit file: {e}")
+        pass
+
+    # Otherwise try to find a file that starts with the name
+    candidates = glob.glob(file_path + "*")
+    exclude_list = [".pyc", "~"]  # exclude binaries and backups
+    files = [f for f in candidates if not any(f.endswith(ext) for ext in exclude_list)]
+    if len(files) > 1:
+        tty.die(
+            f"Multiple files start with `{name}`:\n"
+            + "\n".join(f"        {os.path.basename(f)}" for f in files)
+        )
+    elif not files:
+        tty.die(f"No file for '{name}' was found in {path}")
+    return files[0]
 
 
 def edit(parser, args):
-    name = args.package
-
-    # By default, edit package files
-    path = spack.paths.packages_path
+    names = args.package
 
     # If `--command`, `--test`, or `--module` is chosen, edit those instead
     if args.path:
-        path = args.path
-        if name:
-            # convert command names to python module name
-            if path == spack.paths.command_path:
-                name = spack.cmd.python_name(name)
-
-            path = os.path.join(path, name)
-            if not os.path.exists(path):
-                files = glob.glob(path + "*")
-                exclude_list = [".pyc", "~"]  # exclude binaries and backups
-                files = list(filter(lambda x: all(s not in x for s in exclude_list), files))
-                if len(files) > 1:
-                    m = "Multiple files exist with the name {0}.".format(name)
-                    m += " Please specify a suffix. Files are:\n\n"
-                    for f in files:
-                        m += "        " + os.path.basename(f) + "\n"
-                    tty.die(m)
-                if not files:
-                    tty.die("No file for '{0}' was found in {1}".format(name, path))
-                path = files[0]  # already confirmed only one entry in files
-
-        editor(path)
-    elif name:
-        edit_package(name, args.repo, args.namespace)
+        paths = [locate_file(name, args.path) for name in names] if names else [args.path]
+        spack.util.editor.editor(*paths)
+    elif names:
+        if args.repo:
+            repo = spack.repo.Repo(args.repo)
+        elif args.namespace:
+            repo = spack.repo.PATH.get_repo(args.namespace)
+        else:
+            repo = spack.repo.PATH
+        paths = [locate_package(name, repo) for name in names]
+        spack.util.editor.editor(*paths)
     else:
         # By default open the directory where packages live
-        editor(path)
+        spack.util.editor.editor(spack.paths.packages_path)

lib/spack/spack/cmd/env.py

@@ -10,7 +10,7 @@
 import sys
 import tempfile
 from pathlib import Path
-from typing import Optional
+from typing import List, Optional
 
 import llnl.string as string
 import llnl.util.filesystem as fs
@@ -87,6 +87,9 @@ def env_create_setup_parser(subparser):
         default=None,
         help="either a lockfile (must end with '.json' or '.lock') or a manifest file",
     )
+    subparser.add_argument(
+        "--include-concrete", action="append", help="name of old environment to copy specs from"
+    )
 
 
 def env_create(args):
@@ -104,12 +107,17 @@ def env_create(args):
         # the environment should not include a view.
         with_view = None
 
+    include_concrete = None
+    if hasattr(args, "include_concrete"):
+        include_concrete = args.include_concrete
+
     env = _env_create(
         args.env_name,
         init_file=args.envfile,
         dir=args.dir or os.path.sep in args.env_name or args.env_name in (".", ".."),
         with_view=with_view,
         keep_relative=args.keep_relative,
+        include_concrete=include_concrete,
     )
 
     # Generate views, only really useful for environments created from spack.lock files.
@@ -123,31 +131,43 @@ def _env_create(
     dir: bool = False,
     with_view: Optional[str] = None,
     keep_relative: bool = False,
+    include_concrete: Optional[List[str]] = None,
 ):
     """Create a new environment, with an optional yaml description.
 
     Arguments:
-        name_or_path: name of the environment to create, or path to it
-        init_file: optional initialization file -- can be a JSON lockfile (*.lock, *.json) or YAML
-            manifest file
-        dir: if True, create an environment in a directory instead of a managed environment
-        keep_relative: if True, develop paths are copied verbatim into the new environment file,
-            otherwise they may be made absolute if the new environment is in a different location
+        name_or_path (str): name of the environment to create, or path to it
+        init_file (str or file): optional initialization file -- can be
+            a JSON lockfile (*.lock, *.json) or YAML manifest file
+        dir (bool): if True, create an environment in a directory instead
+            of a named environment
+        keep_relative (bool): if True, develop paths are copied verbatim into
+            the new environment file, otherwise they may be made absolute if the
+            new environment is in a different location
+        include_concrete (list): list of the included concrete environments
     """
     if not dir:
         env = ev.create(
-            name_or_path, init_file=init_file, with_view=with_view, keep_relative=keep_relative
+            name_or_path,
+            init_file=init_file,
+            with_view=with_view,
+            keep_relative=keep_relative,
+            include_concrete=include_concrete,
         )
         tty.msg(
             colorize(
-                f"Created environment @c{{{cescape(env.name)}}} in: @c{{{cescape(env.path)}}}"
+                f"Created environment @c{{{cescape(name_or_path)}}} in: @c{{{cescape(env.path)}}}"
             )
         )
     else:
         env = ev.create_in_dir(
-            name_or_path, init_file=init_file, with_view=with_view, keep_relative=keep_relative
+            name_or_path,
+            init_file=init_file,
+            with_view=with_view,
+            keep_relative=keep_relative,
+            include_concrete=include_concrete,
         )
-        tty.msg(colorize(f"Created anonymous environment in: @c{{{cescape(env.path)}}}"))
+        tty.msg(colorize(f"Created independent environment in: @c{{{cescape(env.path)}}}"))
     tty.msg(f"Activate with: {colorize(f'@c{{spack env activate {cescape(name_or_path)}}}')}")
     return env
 
@@ -434,6 +454,12 @@ def env_remove_setup_parser(subparser):
     """remove an existing environment"""
     subparser.add_argument("rm_env", metavar="env", nargs="+", help="environment(s) to remove")
     arguments.add_common_arguments(subparser, ["yes_to_all"])
+    subparser.add_argument(
+        "-f",
+        "--force",
+        action="store_true",
+        help="remove the environment even if it is included in another environment",
+    )
 
 
 def env_remove(args):
@@ -443,13 +469,35 @@ def env_remove(args):
     and manifests embedded in repositories should be removed manually.
     """
     read_envs = []
+    valid_envs = []
     bad_envs = []
-    for env_name in args.rm_env:
+    invalid_envs = []
+
+    for env_name in ev.all_environment_names():
         try:
             env = ev.read(env_name)
-            read_envs.append(env)
+            valid_envs.append(env_name)
+
+            if env_name in args.rm_env:
+                read_envs.append(env)
         except (spack.config.ConfigFormatError, ev.SpackEnvironmentConfigError):
-            bad_envs.append(env_name)
+            invalid_envs.append(env_name)
+
+            if env_name in args.rm_env:
+                bad_envs.append(env_name)
+
+        # Check if env is linked to another before trying to remove
+        for name in valid_envs:
+            # don't check if environment is included to itself
+            if name == env_name:
+                continue
+            environ = ev.Environment(ev.root(name))
+            if ev.root(env_name) in environ.included_concrete_envs:
+                msg = f'Environment "{env_name}" is being used by environment "{name}"'
+                if args.force:
+                    tty.warn(msg)
+                else:
+                    tty.die(msg)
 
     if not args.yes_to_all:
         environments = string.plural(len(args.rm_env), "environment", show_n=False)

lib/spack/spack/cmd/find.py

@@ -3,6 +3,7 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
+import copy
 import sys
 
 import llnl.util.lang
@@ -271,6 +272,27 @@ def root_decorator(spec, string):
 
     print()
 
+    if env.included_concrete_envs:
+        tty.msg("Included specs")
+
+        # Root specs cannot be displayed with prefixes, since those are not
+        # set for abstract specs. Same for hashes
+        root_args = copy.copy(args)
+        root_args.paths = False
+
+        # Roots are displayed with variants, etc. so that we can see
+        # specifically what the user asked for.
+        cmd.display_specs(
+            env.included_user_specs,
+            root_args,
+            decorator=lambda s, f: color.colorize("@*{%s}" % f),
+            namespace=True,
+            show_flags=True,
+            show_full_compiler=True,
+            variants=True,
+        )
+        print()
+
     if args.show_concretized:
         tty.msg("Concretized roots")
         cmd.display_specs(env.specs_by_hash.values(), args, decorator=decorator)

lib/spack/spack/cmd/help.py

@@ -50,7 +50,7 @@
       @B{++}, @r{--}, @r{~~}, @B{==}                propagate variants to package dependencies
 
     architecture variants:
-      @m{platform=platform}             linux, darwin, cray, etc.
+      @m{platform=platform}             linux, darwin, freebsd, windows
       @m{os=operating_system}           specific <operating_system>
       @m{target=target}                 specific <target> processor
       @m{arch=platform-os-target}       shortcut for all three above

lib/spack/spack/cmd/install.py

@@ -10,6 +10,7 @@
 from typing import List
 
 import llnl.util.filesystem as fs
+from llnl.string import plural
 from llnl.util import lang, tty
 
 import spack.build_environment
@@ -61,7 +62,6 @@ def install_kwargs_from_args(args):
         "dependencies_use_cache": cache_opt(args.use_cache, dep_use_bc),
         "dependencies_cache_only": cache_opt(args.cache_only, dep_use_bc),
         "include_build_deps": args.include_build_deps,
-        "explicit": True,  # Use true as a default for install command
         "stop_at": args.until,
         "unsigned": args.unsigned,
         "install_deps": ("dependencies" in args.things_to_install),
@@ -376,7 +376,9 @@ def _maybe_add_and_concretize(args, env, specs):
         # `spack concretize`
         tests = compute_tests_install_kwargs(env.user_specs, args.test)
         concretized_specs = env.concretize(tests=tests)
-        ev.display_specs(concretized_specs)
+        if concretized_specs:
+            tty.msg(f"Concretized {plural(len(concretized_specs), 'spec')}")
+            ev.display_specs([concrete for _, concrete in concretized_specs])
 
         # save view regeneration for later, so that we only do it
         # once, as it can be slow.
@@ -473,6 +475,7 @@ def install_without_active_env(args, install_kwargs, reporter_factory):
             require_user_confirmation_for_overwrite(concrete_specs, args)
             install_kwargs["overwrite"] = [spec.dag_hash() for spec in concrete_specs]
 
-        installs = [(s.package, install_kwargs) for s in concrete_specs]
-        builder = PackageInstaller(installs)
+        installs = [s.package for s in concrete_specs]
+        install_kwargs["explicit"] = [s.dag_hash() for s in concrete_specs]
+        builder = PackageInstaller(installs, install_kwargs)
         builder.install()

lib/spack/spack/cmd/solve.py

@@ -114,15 +114,16 @@ def _process_result(result, show, required_format, kwargs):
 
     # dump the solutions as concretized specs
     if "solutions" in show:
-        for spec in result.specs:
-            # With -y, just print YAML to output.
-            if required_format == "yaml":
-                # use write because to_yaml already has a newline.
-                sys.stdout.write(spec.to_yaml(hash=ht.dag_hash))
-            elif required_format == "json":
-                sys.stdout.write(spec.to_json(hash=ht.dag_hash))
-            else:
-                sys.stdout.write(spec.tree(color=sys.stdout.isatty(), **kwargs))
+        if required_format:
+            for spec in result.specs:
+                # With -y, just print YAML to output.
+                if required_format == "yaml":
+                    # use write because to_yaml already has a newline.
+                    sys.stdout.write(spec.to_yaml(hash=ht.dag_hash))
+                elif required_format == "json":
+                    sys.stdout.write(spec.to_json(hash=ht.dag_hash))
+        else:
+            sys.stdout.write(spack.spec.tree(result.specs, color=sys.stdout.isatty(), **kwargs))
         print()
 
     if result.unsolved_specs and "solutions" in show:

lib/spack/spack/cmd/spec.py

@@ -105,11 +105,19 @@ def spec(parser, args):
         if env:
             env.concretize()
             specs = env.concretized_specs()
+
+            # environments are printed together in a combined tree() invocation,
+            # except when using --yaml or --json, which we print spec by spec below.
+            if not args.format:
+                tree_kwargs["key"] = spack.traverse.by_dag_hash
+                tree_kwargs["hashes"] = args.long or args.very_long
+                print(spack.spec.tree([concrete for _, concrete in specs], **tree_kwargs))
+                return
         else:
             tty.die("spack spec requires at least one spec or an active environment")
 
     for input, output in specs:
-        # With -y, just print YAML to output.
+        # With --yaml or --json, just print the raw specs to output
         if args.format:
             if args.format == "yaml":
                 # use write because to_yaml already has a newline.

lib/spack/spack/cmd/tutorial.py

@@ -23,7 +23,7 @@
 
 
 # tutorial configuration parameters
-tutorial_branch = "releases/v0.21"
+tutorial_branch = "releases/v0.22"
 tutorial_mirror = "file:///mirror"
 tutorial_key = os.path.join(spack.paths.share_path, "keys", "tutorial.pub")
 

lib/spack/spack/cmd/uninstall.py

@@ -151,7 +151,8 @@ def is_installed(spec):
         key=lambda s: s.dag_hash(),
     )
 
-    return [spec for spec in specs if is_installed(spec)]
+    with spack.store.STORE.db.read_transaction():
+        return [spec for spec in specs if is_installed(spec)]
 
 
 def dependent_environments(
@@ -239,6 +240,8 @@ def get_uninstall_list(args, specs: List[spack.spec.Spec], env: Optional[ev.Envi
             print()
             tty.info("The following environments still reference these specs:")
             colify([e.name for e in other_dependent_envs.keys()], indent=4)
+            if env:
+                msgs.append("use `spack remove` to remove the spec from the current environment")
             msgs.append("use `spack env remove` to remove environments")
         msgs.append("use `spack uninstall --force` to override")
         print()

lib/spack/spack/cmd/unload.py

@@ -71,7 +71,7 @@ def unload(parser, args):
             "Cannot specify specs on command line when unloading all specs with '--all'"
         )
 
-    hashes = os.environ.get(uenv.spack_loaded_hashes_var, "").split(":")
+    hashes = os.environ.get(uenv.spack_loaded_hashes_var, "").split(os.pathsep)
     if args.specs:
         specs = [
             spack.cmd.disambiguate_spec_from_hashes(spec, hashes)

lib/spack/spack/cmd/view.py

@@ -38,10 +38,10 @@
 
 import spack.cmd
 import spack.environment as ev
+import spack.filesystem_view as fsv
 import spack.schema.projections
 import spack.store
 from spack.config import validate
-from spack.filesystem_view import YamlFilesystemView, view_func_parser
 from spack.util import spack_yaml as s_yaml
 
 description = "project packages to a compact naming scheme on the filesystem"
@@ -193,17 +193,13 @@ def view(parser, args):
         ordered_projections = {}
 
     # What method are we using for this view
-    if args.action in actions_link:
-        link_fn = view_func_parser(args.action)
-    else:
-        link_fn = view_func_parser("symlink")
-
-    view = YamlFilesystemView(
+    link_type = args.action if args.action in actions_link else "symlink"
+    view = fsv.YamlFilesystemView(
         path,
         spack.store.STORE.layout,
         projections=ordered_projections,
         ignore_conflicts=getattr(args, "ignore_conflicts", False),
-        link=link_fn,
+        link_type=link_type,
         verbose=args.verbose,
     )
 

lib/spack/spack/compiler.py

@@ -695,10 +695,6 @@ def compiler_environment(self):
         try:
             # load modules and set env variables
             for module in self.modules:
-                # On cray, mic-knl module cannot be loaded without cce module
-                # See: https://github.com/spack/spack/issues/3153
-                if os.environ.get("CRAY_CPU_TARGET") == "mic-knl":
-                    spack.util.module_cmd.load_module("cce")
                 spack.util.module_cmd.load_module(module)
 
             # apply other compiler environment changes

lib/spack/spack/compilers/__init__.py

@@ -220,10 +220,10 @@ def _compiler_config_from_external(config):
         operating_system = host_platform.operating_system("default_os")
         target = host_platform.target("default_target").microarchitecture
     else:
-        target = spec.target
+        target = spec.architecture.target
         if not target:
-            host_platform = spack.platforms.host()
-            target = host_platform.target("default_target").microarchitecture
+            target = spack.platforms.host().target("default_target")
+        target = target.microarchitecture
 
         operating_system = spec.os
         if not operating_system:

lib/spack/spack/compilers/clang.py

@@ -96,6 +96,8 @@ def verbose_flag(self):
 
     openmp_flag = "-fopenmp"
 
+    # C++ flags based on CMake Modules/Compiler/Clang.cmake
+
     @property
     def cxx11_flag(self):
         if self.real_version < Version("3.3"):
@@ -120,6 +122,24 @@ def cxx17_flag(self):
 
         return "-std=c++17"
 
+    @property
+    def cxx20_flag(self):
+        if self.real_version < Version("5.0"):
+            raise UnsupportedCompilerFlag(self, "the C++20 standard", "cxx20_flag", "< 5.0")
+        elif self.real_version < Version("11.0"):
+            return "-std=c++2a"
+        else:
+            return "-std=c++20"
+
+    @property
+    def cxx23_flag(self):
+        if self.real_version < Version("12.0"):
+            raise UnsupportedCompilerFlag(self, "the C++23 standard", "cxx23_flag", "< 12.0")
+        elif self.real_version < Version("17.0"):
+            return "-std=c++2b"
+        else:
+            return "-std=c++23"
+
     @property
     def c99_flag(self):
         return "-std=c99"
@@ -142,7 +162,10 @@ def c17_flag(self):
     def c23_flag(self):
         if self.real_version < Version("9.0"):
             raise UnsupportedCompilerFlag(self, "the C23 standard", "c23_flag", "< 9.0")
-        return "-std=c2x"
+        elif self.real_version < Version("18.0"):
+            return "-std=c2x"
+        else:
+            return "-std=c23"
 
     @property
     def cc_pic_flag(self):

lib/spack/spack/container/images.json

@@ -78,24 +78,17 @@
         "image": "quay.io/almalinuxorg/almalinux:8"
       }
     },
-    "centos:stream": {
+    "centos:stream9": {
       "bootstrap": {
-        "template": "container/centos_stream.dockerfile",
-        "image": "quay.io/centos/centos:stream"
+        "template": "container/centos_stream9.dockerfile",
+        "image": "quay.io/centos/centos:stream9"
       },
       "os_package_manager": "dnf_epel",
-      "build": "spack/centos-stream",
+      "build": "spack/centos-stream9",
       "final": {
-        "image": "quay.io/centos/centos:stream"
+        "image": "quay.io/centos/centos:stream9"
       }
     },
-    "centos:7": {
-      "bootstrap": {
-        "template": "container/centos_7.dockerfile"
-      },
-      "os_package_manager": "yum",
-      "build": "spack/centos7"
-    },
     "opensuse/leap:15": {
       "bootstrap": {
         "template": "container/leap-15.dockerfile"

lib/spack/spack/directory_layout.py

@@ -15,6 +15,7 @@
 
 import llnl.util.filesystem as fs
 import llnl.util.tty as tty
+from llnl.util.symlink import readlink
 
 import spack.config
 import spack.hash_types as ht
@@ -181,7 +182,7 @@ def deprecated_file_path(self, deprecated_spec, deprecator_spec=None):
         base_dir = (
             self.path_for_spec(deprecator_spec)
             if deprecator_spec
-            else os.readlink(deprecated_spec.prefix)
+            else readlink(deprecated_spec.prefix)
         )
 
         yaml_path = os.path.join(

lib/spack/spack/environment/__init__.py

@@ -34,6 +34,9 @@
       * ``spec``: a string representation of the abstract spec that was concretized
 
   4. ``concrete_specs``: a dictionary containing the specs in the environment.
+  5. ``include_concrete`` (dictionary): an optional dictionary that includes the roots
+     and concrete specs from the included environments, keyed by the path to that
+     environment
 
 Compatibility
 -------------
@@ -50,26 +53,37 @@
      - ``v2``
      - ``v3``
      - ``v4``
+     - ``v5``
    * - ``v0.12:0.14``
      - ✅
      -
      -
      -
+     -
    * - ``v0.15:0.16``
      - ✅
      - ✅
      -
      -
+     -
    * - ``v0.17``
      - ✅
      - ✅
      - ✅
      -
+     -
    * - ``v0.18:``
      - ✅
      - ✅
      - ✅
      - ✅
+     -
+   * - ``v0.22:``
+     - ✅
+     - ✅
+     - ✅
+     - ✅
+     - ✅
 
 Version 1
 ---------
@@ -334,6 +348,118 @@
             }
         }
     }
+
+
+Version 5
+---------
+
+Version 5 doesn't change the top-level lockfile format, but an optional dictionary is
+added. The dictionary has the ``root`` and ``concrete_specs`` of the included
+environments, which are keyed by the path to that environment. Since this is optional
+if the environment does not have any included environments ``include_concrete`` will
+not be a part of the lockfile.
+
+.. code-block:: json
+
+    {
+        "_meta": {
+            "file-type": "spack-lockfile",
+            "lockfile-version": 5,
+            "specfile-version": 3
+        },
+        "roots": [
+            {
+                "hash": "<dag_hash 1>",
+                "spec": "<abstract spec 1>"
+            },
+            {
+                "hash": "<dag_hash 2>",
+                "spec": "<abstract spec 2>"
+            }
+        ],
+        "concrete_specs": {
+            "<dag_hash 1>": {
+                "... <spec dict attributes> ...": { },
+                "dependencies": [
+                    {
+                        "name": "depname_1",
+                        "hash": "<dag_hash for depname_1>",
+                        "type": ["build", "link"]
+                    },
+                    {
+                        "name": "depname_2",
+                        "hash": "<dag_hash for depname_2>",
+                        "type": ["build", "link"]
+                    }
+                ],
+                "hash": "<dag_hash 1>",
+            },
+            "<daghash 2>": {
+                "... <spec dict attributes> ...": { },
+                "dependencies": [
+                    {
+                        "name": "depname_3",
+                        "hash": "<dag_hash for depname_3>",
+                        "type": ["build", "link"]
+                    },
+                    {
+                        "name": "depname_4",
+                        "hash": "<dag_hash for depname_4>",
+                        "type": ["build", "link"]
+                    }
+                ],
+                "hash": "<dag_hash 2>"
+            }
+        }
+        "include_concrete": {
+            "<path to environment>": {
+                "roots": [
+                    {
+                        "hash": "<dag_hash 1>",
+                        "spec": "<abstract spec 1>"
+                    },
+                    {
+                        "hash": "<dag_hash 2>",
+                        "spec": "<abstract spec 2>"
+                    }
+                ],
+                "concrete_specs": {
+                    "<dag_hash 1>": {
+                        "... <spec dict attributes> ...": { },
+                        "dependencies": [
+                            {
+                                "name": "depname_1",
+                                "hash": "<dag_hash for depname_1>",
+                                "type": ["build", "link"]
+                            },
+                            {
+                                "name": "depname_2",
+                                "hash": "<dag_hash for depname_2>",
+                                "type": ["build", "link"]
+                            }
+                        ],
+                        "hash": "<dag_hash 1>",
+                    },
+                    "<daghash 2>": {
+                        "... <spec dict attributes> ...": { },
+                        "dependencies": [
+                            {
+                                "name": "depname_3",
+                                "hash": "<dag_hash for depname_3>",
+                                "type": ["build", "link"]
+                            },
+                            {
+                                "name": "depname_4",
+                                "hash": "<dag_hash for depname_4>",
+                                "type": ["build", "link"]
+                            }
+                        ],
+                        "hash": "<dag_hash 2>"
+                    }
+                }
+            }
+        }
+    }
 """
 
 from .environment import (

lib/spack/spack/environment/environment.py

@@ -16,20 +16,22 @@
 import urllib.parse
 import urllib.request
 import warnings
-from typing import Dict, Iterable, List, Optional, Set, Tuple, Union
+from typing import Any, Dict, Iterable, List, Optional, Set, Tuple, Union
 
 import llnl.util.filesystem as fs
 import llnl.util.tty as tty
 import llnl.util.tty.color as clr
 from llnl.util.link_tree import ConflictingSpecsError
-from llnl.util.symlink import symlink
+from llnl.util.symlink import readlink, symlink
 
+import spack.cmd
 import spack.compilers
 import spack.concretize
 import spack.config
 import spack.deptypes as dt
 import spack.error
 import spack.fetch_strategy
+import spack.filesystem_view as fsv
 import spack.hash_types as ht
 import spack.hooks
 import spack.main
@@ -52,7 +54,6 @@
 import spack.util.url
 import spack.version
 from spack import traverse
-from spack.filesystem_view import SimpleFilesystemView, inverse_view_func_parser, view_func_parser
 from spack.installer import PackageInstaller
 from spack.schema.env import TOP_LEVEL_KEY
 from spack.spec import Spec
@@ -159,6 +160,8 @@ def default_manifest_yaml():
 default_view_name = "default"
 # Default behavior to link all packages into views (vs. only root packages)
 default_view_link = "all"
+# The name for any included concrete specs
+included_concrete_name = "include_concrete"
 
 
 def installed_specs():
@@ -293,6 +296,7 @@ def create(
     init_file: Optional[Union[str, pathlib.Path]] = None,
     with_view: Optional[Union[str, pathlib.Path, bool]] = None,
     keep_relative: bool = False,
+    include_concrete: Optional[List[str]] = None,
 ) -> "Environment":
     """Create a managed environment in Spack and returns it.
 
@@ -309,10 +313,15 @@ def create(
             string, it specifies the path to the view
         keep_relative: if True, develop paths are copied verbatim into the new environment file,
             otherwise they are made absolute
+        include_concrete: list of concrete environment names/paths to be included
     """
     environment_dir = environment_dir_from_name(name, exists_ok=False)
     return create_in_dir(
-        environment_dir, init_file=init_file, with_view=with_view, keep_relative=keep_relative
+        environment_dir,
+        init_file=init_file,
+        with_view=with_view,
+        keep_relative=keep_relative,
+        include_concrete=include_concrete,
     )
 
 
@@ -321,6 +330,7 @@ def create_in_dir(
     init_file: Optional[Union[str, pathlib.Path]] = None,
     with_view: Optional[Union[str, pathlib.Path, bool]] = None,
     keep_relative: bool = False,
+    include_concrete: Optional[List[str]] = None,
 ) -> "Environment":
     """Create an environment in the directory passed as input and returns it.
 
@@ -334,6 +344,7 @@ def create_in_dir(
             string, it specifies the path to the view
         keep_relative: if True, develop paths are copied verbatim into the new environment file,
             otherwise they are made absolute
+        include_concrete: concrete environment names/paths to be included
     """
     initialize_environment_dir(root, envfile=init_file)
 
@@ -346,6 +357,12 @@ def create_in_dir(
         if with_view is not None:
             manifest.set_default_view(with_view)
 
+        if include_concrete is not None:
+            set_included_envs_to_env_paths(include_concrete)
+            validate_included_envs_exists(include_concrete)
+            validate_included_envs_concrete(include_concrete)
+            manifest.set_include_concrete(include_concrete)
+
         manifest.flush()
 
     except (spack.config.ConfigFormatError, SpackEnvironmentConfigError) as e:
@@ -419,6 +436,67 @@ def ensure_env_root_path_exists():
         fs.mkdirp(env_root_path())
 
 
+def set_included_envs_to_env_paths(include_concrete: List[str]) -> None:
+    """If the included environment(s) is the environment name
+    it is replaced by the path to the environment
+
+    Args:
+        include_concrete: list of env name or path to env"""
+
+    for i, env_name in enumerate(include_concrete):
+        if is_env_dir(env_name):
+            include_concrete[i] = env_name
+        elif exists(env_name):
+            include_concrete[i] = root(env_name)
+
+
+def validate_included_envs_exists(include_concrete: List[str]) -> None:
+    """Checks that all of the included environments exist
+
+    Args:
+       include_concrete: list of already existing concrete environments to include
+
+    Raises:
+        SpackEnvironmentError: if any of the included environments do not exist
+    """
+
+    missing_envs = set()
+
+    for i, env_name in enumerate(include_concrete):
+        if not is_env_dir(env_name):
+            missing_envs.add(env_name)
+
+    if missing_envs:
+        msg = "The following environment(s) are missing: {0}".format(", ".join(missing_envs))
+        raise SpackEnvironmentError(msg)
+
+
+def validate_included_envs_concrete(include_concrete: List[str]) -> None:
+    """Checks that all of the included environments are concrete
+
+    Args:
+        include_concrete: list of already existing concrete environments to include
+
+    Raises:
+        SpackEnvironmentError: if any of the included environments are not concrete
+    """
+
+    non_concrete_envs = set()
+
+    for env_path in include_concrete:
+        if not os.path.exists(Environment(env_path).lock_path):
+            non_concrete_envs.add(Environment(env_path).name)
+
+    if non_concrete_envs:
+        msg = "The following environment(s) are not concrete: {0}\n" "Please run:".format(
+            ", ".join(non_concrete_envs)
+        )
+        for env in non_concrete_envs:
+            msg += f"\n\t`spack -e {env} concretize`"
+
+        raise SpackEnvironmentError(msg)
+
+
 def all_environment_names():
     """List the names of environments that currently exist."""
     # just return empty if the env path does not exist.  A read-only
@@ -529,7 +607,7 @@ def __init__(
         self.projections = projections
         self.select = select
         self.exclude = exclude
-        self.link_type = view_func_parser(link_type)
+        self.link_type = fsv.canonicalize_link_type(link_type)
         self.link = link
 
     def select_fn(self, spec):
@@ -563,7 +641,7 @@ def to_dict(self):
         if self.exclude:
             ret["exclude"] = self.exclude
         if self.link_type:
-            ret["link_type"] = inverse_view_func_parser(self.link_type)
+            ret["link_type"] = self.link_type
         if self.link != default_view_link:
             ret["link"] = self.link
         return ret
@@ -585,7 +663,7 @@ def _current_root(self):
         if not os.path.islink(self.root):
             return None
 
-        root = os.readlink(self.root)
+        root = readlink(self.root)
         if os.path.isabs(root):
             return root
 
@@ -613,7 +691,7 @@ def get_projection_for_spec(self, spec):
         to exist on the filesystem."""
         return self._view(self.root).get_projection_for_spec(spec)
 
-    def view(self, new: Optional[str] = None) -> SimpleFilesystemView:
+    def view(self, new: Optional[str] = None) -> fsv.SimpleFilesystemView:
         """
         Returns a view object for the *underlying* view directory. This means that the
         self.root symlink is followed, and that the view has to exist on the filesystem
@@ -633,14 +711,14 @@ def view(self, new: Optional[str] = None) -> SimpleFilesystemView:
             )
         return self._view(path)
 
-    def _view(self, root: str) -> SimpleFilesystemView:
+    def _view(self, root: str) -> fsv.SimpleFilesystemView:
         """Returns a view object for a given root dir."""
-        return SimpleFilesystemView(
+        return fsv.SimpleFilesystemView(
             root,
             spack.store.STORE.layout,
             ignore_conflicts=True,
             projections=self.projections,
-            link=self.link_type,
+            link_type=self.link_type,
         )
 
     def __contains__(self, spec):
@@ -821,6 +899,18 @@ def __init__(self, manifest_dir: Union[str, pathlib.Path]) -> None:
         self.specs_by_hash: Dict[str, Spec] = {}
         #: Repository for this environment (memoized)
         self._repo = None
+
+        #: Environment paths for concrete (lockfile) included environments
+        self.included_concrete_envs: List[str] = []
+        #: First-level included concretized spec data from/to the lockfile.
+        self.included_concrete_spec_data: Dict[str, Dict[str, List[str]]] = {}
+        #: User specs from included environments from the last concretization
+        self.included_concretized_user_specs: Dict[str, List[Spec]] = {}
+        #: Roots from included environments with the last concretization, in order
+        self.included_concretized_order: Dict[str, List[str]] = {}
+        #: Concretized specs by hash from the included environments
+        self.included_specs_by_hash: Dict[str, Dict[str, Spec]] = {}
+
         #: Previously active environment
         self._previous_active = None
         self._dev_specs = None
@@ -858,7 +948,7 @@ def _read(self):
 
         if os.path.exists(self.lock_path):
             with open(self.lock_path) as f:
-                read_lock_version = self._read_lockfile(f)
+                read_lock_version = self._read_lockfile(f)["_meta"]["lockfile-version"]
 
             if read_lock_version == 1:
                 tty.debug(f"Storing backup of {self.lock_path} at {self._lock_backup_v1_path}")
@@ -926,6 +1016,20 @@ def add_view(name, values):
         if self.views == dict():
             self.views[default_view_name] = ViewDescriptor(self.path, self.view_path_default)
 
+    def _process_concrete_includes(self):
+        """Extract and load into memory included concrete spec data."""
+        self.included_concrete_envs = self.manifest[TOP_LEVEL_KEY].get(included_concrete_name, [])
+
+        if self.included_concrete_envs:
+            if os.path.exists(self.lock_path):
+                with open(self.lock_path) as f:
+                    data = self._read_lockfile(f)
+
+                if included_concrete_name in data:
+                    self.included_concrete_spec_data = data[included_concrete_name]
+            else:
+                self.include_concrete_envs()
+
     def _construct_state_from_manifest(self):
         """Set up user specs and views from the manifest file."""
         self.spec_lists = collections.OrderedDict()
@@ -942,6 +1046,31 @@ def _construct_state_from_manifest(self):
         self.spec_lists[user_speclist_name] = user_specs
 
         self._process_view(spack.config.get("view", True))
+        self._process_concrete_includes()
+
+    def all_concretized_user_specs(self) -> List[Spec]:
+        """Returns all of the concretized user specs of the environment and
+        its included environment(s)."""
+        concretized_user_specs = self.concretized_user_specs[:]
+        for included_specs in self.included_concretized_user_specs.values():
+            for included in included_specs:
+                # Don't duplicate included spec(s)
+                if included not in concretized_user_specs:
+                    concretized_user_specs.append(included)
+
+        return concretized_user_specs
+
+    def all_concretized_orders(self) -> List[str]:
+        """Returns all of the concretized order of the environment and
+        its included environment(s)."""
+        concretized_order = self.concretized_order[:]
+        for included_concretized_order in self.included_concretized_order.values():
+            for included in included_concretized_order:
+                # Don't duplicate included spec(s)
+                if included not in concretized_order:
+                    concretized_order.append(included)
+
+        return concretized_order
 
     @property
     def user_specs(self):
@@ -966,6 +1095,26 @@ def _read_dev_specs(self):
             dev_specs[name] = local_entry
         return dev_specs
 
+    @property
+    def included_user_specs(self) -> SpecList:
+        """Included concrete user (or root) specs from last concretization."""
+        spec_list = SpecList()
+
+        if not self.included_concrete_envs:
+            return spec_list
+
+        def add_root_specs(included_concrete_specs):
+            # add specs from the include *and* any nested includes it may have
+            for env, info in included_concrete_specs.items():
+                for root_list in info["roots"]:
+                    spec_list.add(root_list["spec"])
+
+                if "include_concrete" in info:
+                    add_root_specs(info["include_concrete"])
+
+        add_root_specs(self.included_concrete_spec_data)
+        return spec_list
+
     def clear(self, re_read=False):
         """Clear the contents of the environment
 
@@ -977,9 +1126,15 @@ def clear(self, re_read=False):
         self.spec_lists[user_speclist_name] = SpecList()
 
         self._dev_specs = {}
-        self.concretized_user_specs = []  # user specs from last concretize
         self.concretized_order = []  # roots of last concretize, in order
+        self.concretized_user_specs = []  # user specs from last concretize
         self.specs_by_hash = {}  # concretized specs by hash
+
+        self.included_concrete_spec_data = {}  # concretized specs from lockfile of included envs
+        self.included_concretized_order = {}  # root specs of the included envs, keyed by env path
+        self.included_concretized_user_specs = {}  # user specs from last concretize's included env
+        self.included_specs_by_hash = {}  # concretized specs by hash from the included envs
+
         self.invalidate_repository_cache()
         self._previous_active = None  # previously active environment
         if not re_read:
@@ -1033,6 +1188,55 @@ def scope_name(self):
         """Name of the config scope of this environment's manifest file."""
         return self.manifest.scope_name
 
+    def include_concrete_envs(self):
+        """Copy and save the included envs' specs internally"""
+
+        lockfile_meta = None
+        root_hash_seen = set()
+        concrete_hash_seen = set()
+        self.included_concrete_spec_data = {}
+
+        for env_path in self.included_concrete_envs:
+            # Check that environment exists
+            if not is_env_dir(env_path):
+                raise SpackEnvironmentError(f"Unable to find env at {env_path}")
+
+            env = Environment(env_path)
+
+            with open(env.lock_path) as f:
+                lockfile_as_dict = env._read_lockfile(f)
+
+            # Lockfile_meta must match each env and use at least format version 5
+            if lockfile_meta is None:
+                lockfile_meta = lockfile_as_dict["_meta"]
+            elif lockfile_meta != lockfile_as_dict["_meta"]:
+                raise SpackEnvironmentError("All lockfile _meta values must match")
+            elif lockfile_meta["lockfile-version"] < 5:
+                raise SpackEnvironmentError("The lockfile format must be at version 5 or higher")
+
+            # Copy unique root specs from env
+            self.included_concrete_spec_data[env_path] = {"roots": []}
+            for root_dict in lockfile_as_dict["roots"]:
+                if root_dict["hash"] not in root_hash_seen:
+                    self.included_concrete_spec_data[env_path]["roots"].append(root_dict)
+                    root_hash_seen.add(root_dict["hash"])
+
+            # Copy unique concrete specs from env
+            for concrete_spec in lockfile_as_dict["concrete_specs"]:
+                if concrete_spec not in concrete_hash_seen:
+                    self.included_concrete_spec_data[env_path].update(
+                        {"concrete_specs": lockfile_as_dict["concrete_specs"]}
+                    )
+                    concrete_hash_seen.add(concrete_spec)
+
+            if "include_concrete" in lockfile_as_dict.keys():
+                self.included_concrete_spec_data[env_path]["include_concrete"] = lockfile_as_dict[
+                    "include_concrete"
+                ]
+
+        self._read_lockfile_dict(self._to_lockfile_dict())
+        self.write()
+
     def destroy(self):
         """Remove this environment from Spack entirely."""
         shutil.rmtree(self.path)
@@ -1232,6 +1436,10 @@ def concretize(self, force=False, tests=False):
         for spec in set(self.concretized_user_specs) - set(self.user_specs):
             self.deconcretize(spec, concrete=False)
 
+        # If a combined env, check updated spec is in the linked envs
+        if self.included_concrete_envs:
+            self.include_concrete_envs()
+
         # Pick the right concretization strategy
         if self.unify == "when_possible":
             return self._concretize_together_where_possible(tests=tests)
@@ -1704,8 +1912,14 @@ def _partition_roots_by_install_status(self):
         of per spec."""
         installed, uninstalled = [], []
         with spack.store.STORE.db.read_transaction():
-            for concretized_hash in self.concretized_order:
-                spec = self.specs_by_hash[concretized_hash]
+            for concretized_hash in self.all_concretized_orders():
+                if concretized_hash in self.specs_by_hash:
+                    spec = self.specs_by_hash[concretized_hash]
+                else:
+                    for env_path in self.included_specs_by_hash.keys():
+                        if concretized_hash in self.included_specs_by_hash[env_path]:
+                            spec = self.included_specs_by_hash[env_path][concretized_hash]
+                            break
                 if not spec.installed or (
                     spec.satisfies("dev_path=*") or spec.satisfies("^dev_path=*")
                 ):
@@ -1735,13 +1949,19 @@ def install_specs(self, specs: Optional[List[Spec]] = None, **install_args):
         specs = specs if specs is not None else roots
 
         # Extend the set of specs to overwrite with modified dev specs and their parents
-        install_args["overwrite"] = (
-            install_args.get("overwrite", []) + self._dev_specs_that_need_overwrite()
+        overwrite: Set[str] = set()
+        overwrite.update(install_args.get("overwrite", []), self._dev_specs_that_need_overwrite())
+        install_args["overwrite"] = overwrite
+
+        explicit: Set[str] = set()
+        explicit.update(
+            install_args.get("explicit", []),
+            (s.dag_hash() for s in specs),
+            (s.dag_hash() for s in roots),
         )
+        install_args["explicit"] = explicit
 
-        installs = [(spec.package, {**install_args, "explicit": spec in roots}) for spec in specs]
-
-        PackageInstaller(installs).install()
+        PackageInstaller([spec.package for spec in specs], install_args).install()
 
     def all_specs_generator(self) -> Iterable[Spec]:
         """Returns a generator for all concrete specs"""
@@ -1785,8 +2005,14 @@ def added_specs(self):
 
     def concretized_specs(self):
         """Tuples of (user spec, concrete spec) for all concrete specs."""
-        for s, h in zip(self.concretized_user_specs, self.concretized_order):
-            yield (s, self.specs_by_hash[h])
+        for s, h in zip(self.all_concretized_user_specs(), self.all_concretized_orders()):
+            if h in self.specs_by_hash:
+                yield (s, self.specs_by_hash[h])
+            else:
+                for env_path in self.included_specs_by_hash.keys():
+                    if h in self.included_specs_by_hash[env_path]:
+                        yield (s, self.included_specs_by_hash[env_path][h])
+                        break
 
     def concrete_roots(self):
         """Same as concretized_specs, except it returns the list of concrete
@@ -1915,8 +2141,7 @@ def _get_environment_specs(self, recurse_dependencies=True):
         If these specs appear under different user_specs, only one copy
         is added to the list returned.
         """
-        specs = [self.specs_by_hash[h] for h in self.concretized_order]
-
+        specs = [self.specs_by_hash[h] for h in self.all_concretized_orders()]
         if recurse_dependencies:
             specs.extend(
                 traverse.traverse_nodes(
@@ -1961,31 +2186,76 @@ def _to_lockfile_dict(self):
             "concrete_specs": concrete_specs,
         }
 
+        if self.included_concrete_envs:
+            data[included_concrete_name] = self.included_concrete_spec_data
+
         return data
 
     def _read_lockfile(self, file_or_json):
         """Read a lockfile from a file or from a raw string."""
         lockfile_dict = sjson.load(file_or_json)
         self._read_lockfile_dict(lockfile_dict)
-        return lockfile_dict["_meta"]["lockfile-version"]
+        return lockfile_dict
+
+    def set_included_concretized_user_specs(
+        self,
+        env_name: str,
+        env_info: Dict[str, Dict[str, Any]],
+        included_json_specs_by_hash: Dict[str, Dict[str, Any]],
+    ) -> Dict[str, Dict[str, Any]]:
+        """Sets all of the concretized user specs from included environments
+        to include those from nested included environments.
+
+        Args:
+           env_name: the name (technically the path) of the included environment
+           env_info: included concrete environment data
+           included_json_specs_by_hash: concrete spec data keyed by hash
+
+        Returns: updated specs_by_hash
+        """
+        self.included_concretized_order[env_name] = []
+        self.included_concretized_user_specs[env_name] = []
+
+        def add_specs(name, info, specs_by_hash):
+            # Add specs from the environment as well as any of its nested
+            # environments.
+            for root_info in info["roots"]:
+                self.included_concretized_order[name].append(root_info["hash"])
+                self.included_concretized_user_specs[name].append(Spec(root_info["spec"]))
+            if "concrete_specs" in info:
+                specs_by_hash.update(info["concrete_specs"])
+
+            if included_concrete_name in info:
+                for included_name, included_info in info[included_concrete_name].items():
+                    if included_name not in self.included_concretized_order:
+                        self.included_concretized_order[included_name] = []
+                        self.included_concretized_user_specs[included_name] = []
+                    add_specs(included_name, included_info, specs_by_hash)
+
+        add_specs(env_name, env_info, included_json_specs_by_hash)
+        return included_json_specs_by_hash
 
     def _read_lockfile_dict(self, d):
         """Read a lockfile dictionary into this environment."""
         self.specs_by_hash = {}
+        self.included_specs_by_hash = {}
+        self.included_concretized_user_specs = {}
+        self.included_concretized_order = {}
 
         roots = d["roots"]
         self.concretized_user_specs = [Spec(r["spec"]) for r in roots]
         self.concretized_order = [r["hash"] for r in roots]
         json_specs_by_hash = d["concrete_specs"]
+        included_json_specs_by_hash = {}
 
-        # Track specs by their lockfile key.  Currently spack uses the finest
-        # grained hash as the lockfile key, while older formats used the build
-        # hash or a previous incarnation of the DAG hash (one that did not
-        # include build deps or package hash).
-        specs_by_hash = {}
+        if included_concrete_name in d:
+            for env_name, env_info in d[included_concrete_name].items():
+                included_json_specs_by_hash.update(
+                    self.set_included_concretized_user_specs(
+                        env_name, env_info, included_json_specs_by_hash
+                    )
+                )
 
-        # Track specs by their DAG hash, allows handling DAG hash collisions
-        first_seen = {}
         current_lockfile_format = d["_meta"]["lockfile-version"]
         try:
             reader = READER_CLS[current_lockfile_format]
@@ -1998,6 +2268,39 @@ def _read_lockfile_dict(self, d):
                 msg += " You need to use a newer Spack version."
             raise SpackEnvironmentError(msg)
 
+        first_seen, self.concretized_order = self.filter_specs(
+            reader, json_specs_by_hash, self.concretized_order
+        )
+
+        for spec_dag_hash in self.concretized_order:
+            self.specs_by_hash[spec_dag_hash] = first_seen[spec_dag_hash]
+
+        if any(self.included_concretized_order.values()):
+            first_seen = {}
+
+            for env_name, concretized_order in self.included_concretized_order.items():
+                filtered_spec, self.included_concretized_order[env_name] = self.filter_specs(
+                    reader, included_json_specs_by_hash, concretized_order
+                )
+                first_seen.update(filtered_spec)
+
+            for env_path, spec_hashes in self.included_concretized_order.items():
+                self.included_specs_by_hash[env_path] = {}
+                for spec_dag_hash in spec_hashes:
+                    self.included_specs_by_hash[env_path].update(
+                        {spec_dag_hash: first_seen[spec_dag_hash]}
+                    )
+
+    def filter_specs(self, reader, json_specs_by_hash, order_concretized):
+        # Track specs by their lockfile key.  Currently spack uses the finest
+        # grained hash as the lockfile key, while older formats used the build
+        # hash or a previous incarnation of the DAG hash (one that did not
+        # include build deps or package hash).
+        specs_by_hash = {}
+
+        # Track specs by their DAG hash, allows handling DAG hash collisions
+        first_seen = {}
+
         # First pass: Put each spec in the map ignoring dependencies
         for lockfile_key, node_dict in json_specs_by_hash.items():
             spec = reader.from_node_dict(node_dict)
@@ -2020,7 +2323,8 @@ def _read_lockfile_dict(self, d):
         # keep.  This is only required as long as we support older lockfile
         # formats where the mapping from DAG hash to lockfile key is possibly
         # one-to-many.
-        for lockfile_key in self.concretized_order:
+
+        for lockfile_key in order_concretized:
             for s in specs_by_hash[lockfile_key].traverse():
                 if s.dag_hash() not in first_seen:
                     first_seen[s.dag_hash()] = s
@@ -2028,12 +2332,10 @@ def _read_lockfile_dict(self, d):
         # Now make sure concretized_order and our internal specs dict
         # contains the keys used by modern spack (i.e. the dag_hash
         # that includes build deps and package hash).
-        self.concretized_order = [
-            specs_by_hash[h_key].dag_hash() for h_key in self.concretized_order
-        ]
 
-        for spec_dag_hash in self.concretized_order:
-            self.specs_by_hash[spec_dag_hash] = first_seen[spec_dag_hash]
+        order_concretized = [specs_by_hash[h_key].dag_hash() for h_key in order_concretized]
+
+        return first_seen, order_concretized
 
     def write(self, regenerate: bool = True) -> None:
         """Writes an in-memory environment to its location on disk.
@@ -2046,7 +2348,7 @@ def write(self, regenerate: bool = True) -> None:
             regenerate: regenerate views and run post-write hooks as well as writing if True.
         """
         self.manifest_uptodate_or_warn()
-        if self.specs_by_hash:
+        if self.specs_by_hash or self.included_concrete_envs:
             self.ensure_env_directory_exists(dot_env=True)
             self.update_environment_repository()
             self.manifest.flush()
@@ -2172,27 +2474,21 @@ def _equiv_dict(first, second):
     return same_values and same_keys_with_same_overrides
 
 
-def display_specs(concretized_specs):
-    """Displays the list of specs returned by `Environment.concretize()`.
+def display_specs(specs):
+    """Displays a list of specs traversed breadth-first, covering nodes, with install status.
 
     Args:
-        concretized_specs (list): list of specs returned by
-            `Environment.concretize()`
+        specs (list): list of specs
     """
-
-    def _tree_to_display(spec):
-        return spec.tree(
-            recurse_dependencies=True,
-            format=spack.spec.DISPLAY_FORMAT,
-            status_fn=spack.spec.Spec.install_status,
-            hashlen=7,
-            hashes=True,
-        )
-
-    for user_spec, concrete_spec in concretized_specs:
-        tty.msg("Concretized {0}".format(user_spec))
-        sys.stdout.write(_tree_to_display(concrete_spec))
-        print("")
+    tree_string = spack.spec.tree(
+        specs,
+        format=spack.spec.DISPLAY_FORMAT,
+        hashes=True,
+        hashlen=7,
+        status_fn=spack.spec.Spec.install_status,
+        key=traverse.by_dag_hash,
+    )
+    print(tree_string)
 
 
 def _concretize_from_constraints(spec_constraints, tests=False):
@@ -2545,6 +2841,19 @@ def override_user_spec(self, user_spec: str, idx: int) -> None:
             raise SpackEnvironmentError(msg) from e
         self.changed = True
 
+    def set_include_concrete(self, include_concrete: List[str]) -> None:
+        """Sets the included concrete environments in the manifest to the value(s) passed as input.
+
+        Args:
+            include_concrete: list of already existing concrete environments to include
+        """
+        self.pristine_configuration[included_concrete_name] = []
+
+        for env_path in include_concrete:
+            self.pristine_configuration[included_concrete_name].append(env_path)
+
+        self.changed = True
+
     def add_definition(self, user_spec: str, list_name: str) -> None:
         """Appends a user spec to the first active definition matching the name passed as argument.
 
@@ -2728,54 +3037,56 @@ def included_config_scopes(self) -> List[spack.config.ConfigScope]:
         for i, config_path in enumerate(reversed(includes)):
             # allow paths to contain spack config/environment variables, etc.
             config_path = substitute_path_variables(config_path)
-
             include_url = urllib.parse.urlparse(config_path)
 
-            # Transform file:// URLs to direct includes.
-            if include_url.scheme == "file":
-                config_path = urllib.request.url2pathname(include_url.path)
+            # If scheme is not valid, config_path is not a url
+            # of a type Spack is generally aware
+            if spack.util.url.validate_scheme(include_url.scheme):
+                # Transform file:// URLs to direct includes.
+                if include_url.scheme == "file":
+                    config_path = urllib.request.url2pathname(include_url.path)
 
-            # Any other URL should be fetched.
-            elif include_url.scheme in ("http", "https", "ftp"):
-                # Stage any remote configuration file(s)
-                staged_configs = (
-                    os.listdir(self.config_stage_dir)
-                    if os.path.exists(self.config_stage_dir)
-                    else []
-                )
-                remote_path = urllib.request.url2pathname(include_url.path)
-                basename = os.path.basename(remote_path)
-                if basename in staged_configs:
-                    # Do NOT re-stage configuration files over existing
-                    # ones with the same name since there is a risk of
-                    # losing changes (e.g., from 'spack config update').
-                    tty.warn(
-                        "Will not re-stage configuration from {0} to avoid "
-                        "losing changes to the already staged file of the "
-                        "same name.".format(remote_path)
+                # Any other URL should be fetched.
+                elif include_url.scheme in ("http", "https", "ftp"):
+                    # Stage any remote configuration file(s)
+                    staged_configs = (
+                        os.listdir(self.config_stage_dir)
+                        if os.path.exists(self.config_stage_dir)
+                        else []
                     )
-
-                    # Recognize the configuration stage directory
-                    # is flattened to ensure a single copy of each
-                    # configuration file.
-                    config_path = self.config_stage_dir
-                    if basename.endswith(".yaml"):
-                        config_path = os.path.join(config_path, basename)
-                else:
-                    staged_path = spack.config.fetch_remote_configs(
-                        config_path, str(self.config_stage_dir), skip_existing=True
-                    )
-                    if not staged_path:
-                        raise SpackEnvironmentError(
-                            "Unable to fetch remote configuration {0}".format(config_path)
+                    remote_path = urllib.request.url2pathname(include_url.path)
+                    basename = os.path.basename(remote_path)
+                    if basename in staged_configs:
+                        # Do NOT re-stage configuration files over existing
+                        # ones with the same name since there is a risk of
+                        # losing changes (e.g., from 'spack config update').
+                        tty.warn(
+                            "Will not re-stage configuration from {0} to avoid "
+                            "losing changes to the already staged file of the "
+                            "same name.".format(remote_path)
                         )
-                    config_path = staged_path
 
-            elif include_url.scheme:
-                raise ValueError(
-                    f"Unsupported URL scheme ({include_url.scheme}) for "
-                    f"environment include: {config_path}"
-                )
+                        # Recognize the configuration stage directory
+                        # is flattened to ensure a single copy of each
+                        # configuration file.
+                        config_path = self.config_stage_dir
+                        if basename.endswith(".yaml"):
+                            config_path = os.path.join(config_path, basename)
+                    else:
+                        staged_path = spack.config.fetch_remote_configs(
+                            config_path, str(self.config_stage_dir), skip_existing=True
+                        )
+                        if not staged_path:
+                            raise SpackEnvironmentError(
+                                "Unable to fetch remote configuration {0}".format(config_path)
+                            )
+                        config_path = staged_path
+
+                elif include_url.scheme:
+                    raise ValueError(
+                        f"Unsupported URL scheme ({include_url.scheme}) for "
+                        f"environment include: {config_path}"
+                    )
 
             # treat relative paths as relative to the environment
             if not os.path.isabs(config_path):

lib/spack/spack/filesystem_view.py

@@ -10,8 +10,9 @@
 import shutil
 import stat
 import sys
-from typing import Optional
+from typing import Callable, Dict, Optional
 
+from llnl.string import comma_or
 from llnl.util import tty
 from llnl.util.filesystem import (
     mkdirp,
@@ -49,19 +50,20 @@
 _projections_path = ".spack/projections.yaml"
 
 
-def view_symlink(src, dst, **kwargs):
-    # keyword arguments are irrelevant
-    # here to fit required call signature
+LinkCallbackType = Callable[[str, str, "FilesystemView", Optional["spack.spec.Spec"]], None]
+
+
+def view_symlink(src: str, dst: str, *args, **kwargs) -> None:
     symlink(src, dst)
 
 
-def view_hardlink(src, dst, **kwargs):
-    # keyword arguments are irrelevant
-    # here to fit required call signature
+def view_hardlink(src: str, dst: str, *args, **kwargs) -> None:
     os.link(src, dst)
 
 
-def view_copy(src: str, dst: str, view, spec: Optional[spack.spec.Spec] = None):
+def view_copy(
+    src: str, dst: str, view: "FilesystemView", spec: Optional["spack.spec.Spec"] = None
+) -> None:
     """
     Copy a file from src to dst.
 
@@ -104,27 +106,40 @@ def view_copy(src: str, dst: str, view, spec: Optional[spack.spec.Spec] = None):
         tty.debug(f"Can't change the permissions for {dst}")
 
 
-def view_func_parser(parsed_name):
-    # What method are we using for this view
-    if parsed_name in ("hardlink", "hard"):
+#: supported string values for `link_type` in an env, mapped to canonical values
+_LINK_TYPES = {
+    "hardlink": "hardlink",
+    "hard": "hardlink",
+    "copy": "copy",
+    "relocate": "copy",
+    "add": "symlink",
+    "symlink": "symlink",
+    "soft": "symlink",
+}
+
+_VALID_LINK_TYPES = sorted(set(_LINK_TYPES.values()))
+
+
+def canonicalize_link_type(link_type: str) -> str:
+    """Return canonical"""
+    canonical = _LINK_TYPES.get(link_type)
+    if not canonical:
+        raise ValueError(
+            f"Invalid link type: '{link_type}. Must be one of {comma_or(_VALID_LINK_TYPES)}'"
+        )
+    return canonical
+
+
+def function_for_link_type(link_type: str) -> LinkCallbackType:
+    link_type = canonicalize_link_type(link_type)
+    if link_type == "hardlink":
         return view_hardlink
-    elif parsed_name in ("copy", "relocate"):
-        return view_copy
-    elif parsed_name in ("add", "symlink", "soft"):
+    elif link_type == "symlink":
         return view_symlink
-    else:
-        raise ValueError(f"invalid link type for view: '{parsed_name}'")
+    elif link_type == "copy":
+        return view_copy
 
-
-def inverse_view_func_parser(view_type):
-    # get string based on view type
-    if view_type is view_hardlink:
-        link_name = "hardlink"
-    elif view_type is view_copy:
-        link_name = "copy"
-    else:
-        link_name = "symlink"
-    return link_name
+    assert False, "invalid link type"  # need mypy Literal values
 
 
 class FilesystemView:
@@ -140,7 +155,16 @@ class FilesystemView:
     directory structure.
     """
 
-    def __init__(self, root, layout, **kwargs):
+    def __init__(
+        self,
+        root: str,
+        layout: "spack.directory_layout.DirectoryLayout",
+        *,
+        projections: Optional[Dict] = None,
+        ignore_conflicts: bool = False,
+        verbose: bool = False,
+        link_type: str = "symlink",
+    ):
         """
         Initialize a filesystem view under the given `root` directory with
         corresponding directory `layout`.
@@ -149,15 +173,14 @@ def __init__(self, root, layout, **kwargs):
         """
         self._root = root
         self.layout = layout
+        self.projections = {} if projections is None else projections
 
-        self.projections = kwargs.get("projections", {})
-
-        self.ignore_conflicts = kwargs.get("ignore_conflicts", False)
-        self.verbose = kwargs.get("verbose", False)
+        self.ignore_conflicts = ignore_conflicts
+        self.verbose = verbose
 
         # Setup link function to include view
-        link_func = kwargs.get("link", view_symlink)
-        self.link = ft.partial(link_func, view=self)
+        self.link_type = link_type
+        self.link = ft.partial(function_for_link_type(link_type), view=self)
 
     def add_specs(self, *specs, **kwargs):
         """
@@ -255,8 +278,24 @@ class YamlFilesystemView(FilesystemView):
     Filesystem view to work with a yaml based directory layout.
     """
 
-    def __init__(self, root, layout, **kwargs):
-        super().__init__(root, layout, **kwargs)
+    def __init__(
+        self,
+        root: str,
+        layout: "spack.directory_layout.DirectoryLayout",
+        *,
+        projections: Optional[Dict] = None,
+        ignore_conflicts: bool = False,
+        verbose: bool = False,
+        link_type: str = "symlink",
+    ):
+        super().__init__(
+            root,
+            layout,
+            projections=projections,
+            ignore_conflicts=ignore_conflicts,
+            verbose=verbose,
+            link_type=link_type,
+        )
 
         # Super class gets projections from the kwargs
         # YAML specific to get projections from YAML file
@@ -638,9 +677,6 @@ class SimpleFilesystemView(FilesystemView):
     """A simple and partial implementation of FilesystemView focused on performance and immutable
     views, where specs cannot be removed after they were added."""
 
-    def __init__(self, root, layout, **kwargs):
-        super().__init__(root, layout, **kwargs)
-
     def _sanity_check_view_projection(self, specs):
         """A very common issue is that we end up with two specs of the same package, that project
         to the same prefix. We want to catch that as early as possible and give a sensible error to

lib/spack/spack/hooks/absolutify_elf_sonames.py

@@ -13,7 +13,6 @@
 import spack.config
 import spack.relocate
 from spack.util.elf import ElfParsingError, parse_elf
-from spack.util.executable import Executable
 
 
 def is_shared_library_elf(filepath):
@@ -141,7 +140,7 @@ def post_install(spec, explicit=None):
         return
 
     # Only enable on platforms using ELF.
-    if not spec.satisfies("platform=linux") and not spec.satisfies("platform=cray"):
+    if not spec.satisfies("platform=linux"):
         return
 
     # Disable this hook when bootstrapping, to avoid recursion.
@@ -149,10 +148,9 @@ def post_install(spec, explicit=None):
         return
 
     # Should failing to locate patchelf be a hard error?
-    patchelf_path = spack.relocate._patchelf()
-    if not patchelf_path:
+    patchelf = spack.relocate._patchelf()
+    if not patchelf:
         return
-    patchelf = Executable(patchelf_path)
 
     fixes = find_and_patch_sonames(spec.prefix, spec.package.non_bindable_shared_objects, patchelf)
 

lib/spack/spack/hooks/drop_redundant_rpaths.py

@@ -117,7 +117,7 @@ def post_install(spec, explicit=None):
         return
 
     # Only enable on platforms using ELF.
-    if not spec.satisfies("platform=linux") and not spec.satisfies("platform=cray"):
+    if not spec.satisfies("platform=linux"):
         return
 
     visit_directory_tree(spec.prefix, ElfFilesWithRPathVisitor())

lib/spack/spack/installer.py

@@ -488,6 +488,7 @@ def _process_binary_cache_tarball(
 
     with timer.measure("install"), spack.util.path.filter_padding():
         binary_distribution.extract_tarball(pkg.spec, download_result, force=False, timer=timer)
+        pkg.windows_establish_runtime_linkage()
 
         if hasattr(pkg, "_post_buildcache_install_hook"):
             pkg._post_buildcache_install_hook()
@@ -599,9 +600,7 @@ def dump_packages(spec: "spack.spec.Spec", path: str) -> None:
         if node is spec:
             spack.repo.PATH.dump_provenance(node, dest_pkg_dir)
         elif source_pkg_dir:
-            fs.install_tree(
-                source_pkg_dir, dest_pkg_dir, allow_broken_symlinks=(sys.platform != "win32")
-            )
+            fs.install_tree(source_pkg_dir, dest_pkg_dir)
 
 
 def get_dependent_ids(spec: "spack.spec.Spec") -> List[str]:
@@ -760,12 +759,8 @@ def __init__(self, pkg: "spack.package_base.PackageBase", install_args: dict):
         if not self.pkg.spec.concrete:
             raise ValueError(f"{self.pkg.name} must have a concrete spec")
 
-        # Cache the package phase options with the explicit package,
-        # popping the options to ensure installation of associated
-        # dependencies is NOT affected by these options.
-
-        self.pkg.stop_before_phase = install_args.pop("stop_before", None)  # type: ignore[attr-defined] # noqa: E501
-        self.pkg.last_phase = install_args.pop("stop_at", None)  # type: ignore[attr-defined]
+        self.pkg.stop_before_phase = install_args.get("stop_before")  # type: ignore[attr-defined] # noqa: E501
+        self.pkg.last_phase = install_args.get("stop_at")  # type: ignore[attr-defined]
 
         # Cache the package id for convenience
         self.pkg_id = package_id(pkg.spec)
@@ -1075,19 +1070,17 @@ def flag_installed(self, installed: List[str]) -> None:
 
     @property
     def explicit(self) -> bool:
-        """The package was explicitly requested by the user."""
-        return self.is_root and self.request.install_args.get("explicit", True)
+        return self.pkg.spec.dag_hash() in self.request.install_args.get("explicit", [])
 
     @property
-    def is_root(self) -> bool:
-        """The package was requested directly, but may or may not be explicit
-        in an environment."""
+    def is_build_request(self) -> bool:
+        """The package was requested directly"""
         return self.pkg == self.request.pkg
 
     @property
     def use_cache(self) -> bool:
         _use_cache = True
-        if self.is_root:
+        if self.is_build_request:
             return self.request.install_args.get("package_use_cache", _use_cache)
         else:
             return self.request.install_args.get("dependencies_use_cache", _use_cache)
@@ -1095,7 +1088,7 @@ def use_cache(self) -> bool:
     @property
     def cache_only(self) -> bool:
         _cache_only = False
-        if self.is_root:
+        if self.is_build_request:
             return self.request.install_args.get("package_cache_only", _cache_only)
         else:
             return self.request.install_args.get("dependencies_cache_only", _cache_only)
@@ -1121,24 +1114,17 @@ def priority(self):
 
 class PackageInstaller:
     """
-    Class for managing the install process for a Spack instance based on a
-    bottom-up DAG approach.
+    Class for managing the install process for a Spack instance based on a bottom-up DAG approach.
 
-    This installer can coordinate concurrent batch and interactive, local
-    and distributed (on a shared file system) builds for the same Spack
-    instance.
+    This installer can coordinate concurrent batch and interactive, local and distributed (on a
+    shared file system) builds for the same Spack instance.
     """
 
-    def __init__(self, installs: List[Tuple["spack.package_base.PackageBase", dict]] = []) -> None:
-        """Initialize the installer.
-
-        Args:
-            installs (list): list of tuples, where each
-                tuple consists of a package (PackageBase) and its associated
-                 install arguments (dict)
-        """
+    def __init__(
+        self, packages: List["spack.package_base.PackageBase"], install_args: dict
+    ) -> None:
         # List of build requests
-        self.build_requests = [BuildRequest(pkg, install_args) for pkg, install_args in installs]
+        self.build_requests = [BuildRequest(pkg, install_args) for pkg in packages]
 
         # Priority queue of build tasks
         self.build_pq: List[Tuple[Tuple[int, int], BuildTask]] = []
@@ -1556,17 +1542,6 @@ def _add_tasks(self, request: BuildRequest, all_deps):
             tty.warn(f"Installation request refused: {str(err)}")
             return
 
-        # Skip out early if the spec is not being installed locally (i.e., if
-        # external or upstream).
-        #
-        # External and upstream packages need to get flagged as installed to
-        # ensure proper status tracking for environment build.
-        explicit = request.install_args.get("explicit", True)
-        not_local = _handle_external_and_upstream(request.pkg, explicit)
-        if not_local:
-            self._flag_installed(request.pkg)
-            return
-
         install_compilers = spack.config.get("config:install_missing_compilers", False)
 
         install_deps = request.install_args.get("install_deps")
@@ -1682,10 +1657,6 @@ def _install_task(self, task: BuildTask, install_status: InstallStatus) -> None:
         if not pkg.unit_test_check():
             return
 
-        # Injecting information to know if this installation request is the root one
-        # to determine in BuildProcessInstaller whether installation is explicit or not
-        install_args["is_root"] = task.is_root
-
         try:
             self._setup_install_dir(pkg)
 
@@ -1997,8 +1968,8 @@ def install(self) -> None:
 
         self._init_queue()
         fail_fast_err = "Terminating after first install failure"
-        single_explicit_spec = len(self.build_requests) == 1
-        failed_explicits = []
+        single_requested_spec = len(self.build_requests) == 1
+        failed_build_requests = []
 
         install_status = InstallStatus(len(self.build_pq))
 
@@ -2047,11 +2018,10 @@ def install(self) -> None:
             # Skip the installation if the spec is not being installed locally
             # (i.e., if external or upstream) BUT flag it as installed since
             # some package likely depends on it.
-            if not task.explicit:
-                if _handle_external_and_upstream(pkg, False):
-                    term_status.clear()
-                    self._flag_installed(pkg, task.dependents)
-                    continue
+            if _handle_external_and_upstream(pkg, task.explicit):
+                term_status.clear()
+                self._flag_installed(pkg, task.dependents)
+                continue
 
             # Flag a failed spec.  Do not need an (install) prefix lock since
             # assume using a separate (failed) prefix lock file.
@@ -2196,14 +2166,11 @@ def install(self) -> None:
                 if self.fail_fast:
                     raise InstallError(f"{fail_fast_err}: {str(exc)}", pkg=pkg)
 
-                # Terminate at this point if the single explicit spec has
-                # failed to install.
-                if single_explicit_spec and task.explicit:
-                    raise
-
-                # Track explicit spec id and error to summarize when done
-                if task.explicit:
-                    failed_explicits.append((pkg, pkg_id, str(exc)))
+                # Terminate when a single build request has failed, or summarize errors later.
+                if task.is_build_request:
+                    if single_requested_spec:
+                        raise
+                    failed_build_requests.append((pkg, pkg_id, str(exc)))
 
             finally:
                 # Remove the install prefix if anything went wrong during
@@ -2226,16 +2193,16 @@ def install(self) -> None:
             if request.install_args.get("install_package") and request.pkg_id not in self.installed
         ]
 
-        if failed_explicits or missing:
-            for _, pkg_id, err in failed_explicits:
+        if failed_build_requests or missing:
+            for _, pkg_id, err in failed_build_requests:
                 tty.error(f"{pkg_id}: {err}")
 
             for _, pkg_id in missing:
                 tty.error(f"{pkg_id}: Package was not installed")
 
-            if len(failed_explicits) > 0:
-                pkg = failed_explicits[0][0]
-                ids = [pkg_id for _, pkg_id, _ in failed_explicits]
+            if len(failed_build_requests) > 0:
+                pkg = failed_build_requests[0][0]
+                ids = [pkg_id for _, pkg_id, _ in failed_build_requests]
                 tty.debug(
                     "Associating installation failure with first failed "
                     f"explicit package ({ids[0]}) from {', '.join(ids)}"
@@ -2294,7 +2261,7 @@ def __init__(self, pkg: "spack.package_base.PackageBase", install_args: dict):
         self.verbose = bool(install_args.get("verbose", False))
 
         # whether installation was explicitly requested by the user
-        self.explicit = install_args.get("is_root", False) and install_args.get("explicit", True)
+        self.explicit = pkg.spec.dag_hash() in install_args.get("explicit", [])
 
         # env before starting installation
         self.unmodified_env = install_args.get("unmodified_env", {})
@@ -2379,9 +2346,7 @@ def _install_source(self) -> None:
         src_target = os.path.join(pkg.spec.prefix, "share", pkg.name, "src")
         tty.debug(f"{self.pre} Copying source to {src_target}")
 
-        fs.install_tree(
-            pkg.stage.source_path, src_target, allow_broken_symlinks=(sys.platform != "win32")
-        )
+        fs.install_tree(pkg.stage.source_path, src_target)
 
     def _real_install(self) -> None:
         import spack.builder

lib/spack/spack/oci/oci.py

@@ -11,7 +11,7 @@
 import urllib.parse
 import urllib.request
 from http.client import HTTPResponse
-from typing import NamedTuple, Tuple
+from typing import List, NamedTuple, Tuple
 from urllib.request import Request
 
 import llnl.util.tty as tty
@@ -27,6 +27,7 @@
 import spack.stage
 import spack.traverse
 import spack.util.crypto
+import spack.util.url
 
 from .image import Digest, ImageReference
 
@@ -69,6 +70,42 @@ def with_query_param(url: str, param: str, value: str) -> str:
     )
 
 
+def list_tags(ref: ImageReference, _urlopen: spack.oci.opener.MaybeOpen = None) -> List[str]:
+    """Retrieves the list of tags associated with an image, handling pagination."""
+    _urlopen = _urlopen or spack.oci.opener.urlopen
+    tags = set()
+    fetch_url = ref.tags_url()
+
+    while True:
+        # Fetch tags
+        request = Request(url=fetch_url)
+        response = _urlopen(request)
+        spack.oci.opener.ensure_status(request, response, 200)
+        tags.update(json.load(response)["tags"])
+
+        # Check for pagination
+        link_header = response.headers["Link"]
+
+        if link_header is None:
+            break
+
+        tty.debug(f"OCI tag pagination: {link_header}")
+
+        rel_next_value = spack.util.url.parse_link_rel_next(link_header)
+
+        if rel_next_value is None:
+            break
+
+        rel_next = urllib.parse.urlparse(rel_next_value)
+
+        if rel_next.scheme not in ("https", ""):
+            break
+
+        fetch_url = ref.endpoint(rel_next_value)
+
+    return sorted(tags)
+
+
 def upload_blob(
     ref: ImageReference,
     file: str,

lib/spack/spack/oci/opener.py

@@ -418,18 +418,27 @@ def ensure_status(request: urllib.request.Request, response: HTTPResponse, statu
     )
 
 
-def default_retry(f, retries: int = 3, sleep=None):
+def default_retry(f, retries: int = 5, sleep=None):
     sleep = sleep or time.sleep
 
     def wrapper(*args, **kwargs):
         for i in range(retries):
             try:
                 return f(*args, **kwargs)
-            except urllib.error.HTTPError as e:
+            except (urllib.error.URLError, TimeoutError) as e:
                 # Retry on internal server errors, and rate limit errors
                 # Potentially this could take into account the Retry-After header
                 # if registries support it
-                if i + 1 != retries and (500 <= e.code < 600 or e.code == 429):
+                if i + 1 != retries and (
+                    (
+                        isinstance(e, urllib.error.HTTPError)
+                        and (500 <= e.code < 600 or e.code == 429)
+                    )
+                    or (
+                        isinstance(e, urllib.error.URLError) and isinstance(e.reason, TimeoutError)
+                    )
+                    or isinstance(e, TimeoutError)
+                ):
                     # Exponential backoff
                     sleep(2**i)
                     continue

lib/spack/spack/operating_systems/__init__.py

@@ -3,22 +3,12 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 from ._operating_system import OperatingSystem
-from .cray_backend import CrayBackend
-from .cray_frontend import CrayFrontend
 from .freebsd import FreeBSDOs
 from .linux_distro import LinuxDistro
 from .mac_os import MacOs
 from .windows_os import WindowsOs
 
-__all__ = [
-    "OperatingSystem",
-    "LinuxDistro",
-    "MacOs",
-    "CrayFrontend",
-    "CrayBackend",
-    "WindowsOs",
-    "FreeBSDOs",
-]
+__all__ = ["OperatingSystem", "LinuxDistro", "MacOs", "WindowsOs", "FreeBSDOs"]
 
 #: List of all the Operating Systems known to Spack
-operating_systems = [LinuxDistro, MacOs, CrayFrontend, CrayBackend, WindowsOs, FreeBSDOs]
+operating_systems = [LinuxDistro, MacOs, WindowsOs, FreeBSDOs]

lib/spack/spack/operating_systems/cray_backend.py

@@ -1,172 +0,0 @@
-# Copyright 2013-2024 Lawrence Livermore National Security, LLC and other
-# Spack Project Developers. See the top-level COPYRIGHT file for details.
-#
-# SPDX-License-Identifier: (Apache-2.0 OR MIT)
-
-import os
-import re
-
-import llnl.util.tty as tty
-
-import spack.error
-import spack.version
-from spack.util.module_cmd import module
-
-from .linux_distro import LinuxDistro
-
-#: Possible locations of the Cray CLE release file,
-#: which we look at to get the CNL OS version.
-_cle_release_file = "/etc/opt/cray/release/cle-release"
-_clerelease_file = "/etc/opt/cray/release/clerelease"
-
-
-def read_cle_release_file():
-    """Read the CLE release file and return a dict with its attributes.
-
-    This file is present on newer versions of Cray.
-
-    The release file looks something like this::
-
-        RELEASE=6.0.UP07
-        BUILD=6.0.7424
-        ...
-
-    The dictionary we produce looks like this::
-
-        {
-          "RELEASE": "6.0.UP07",
-          "BUILD": "6.0.7424",
-          ...
-        }
-
-    Returns:
-        dict: dictionary of release attributes
-    """
-    with open(_cle_release_file) as release_file:
-        result = {}
-        for line in release_file:
-            # use partition instead of split() to ensure we only split on
-            # the first '=' in the line.
-            key, _, value = line.partition("=")
-            result[key] = value.strip()
-        return result
-
-
-def read_clerelease_file():
-    """Read the CLE release file and return the Cray OS version.
-
-    This file is present on older versions of Cray.
-
-    The release file looks something like this::
-
-        5.2.UP04
-
-    Returns:
-        str: the Cray OS version
-    """
-    with open(_clerelease_file) as release_file:
-        for line in release_file:
-            return line.strip()
-
-
-class CrayBackend(LinuxDistro):
-    """Compute Node Linux (CNL) is the operating system used for the Cray XC
-    series super computers. It is a very stripped down version of GNU/Linux.
-    Any compilers found through this operating system will be used with
-    modules. If updated, user must make sure that version and name are
-    updated to indicate that OS has been upgraded (or downgraded)
-    """
-
-    def __init__(self):
-        name = "cnl"
-        version = self._detect_crayos_version()
-        if version:
-            # If we found a CrayOS version, we do not want the information
-            # from LinuxDistro. In order to skip the logic from
-            # distro.linux_distribution, while still calling __init__
-            # methods further up the MRO, we skip LinuxDistro in the MRO and
-            # call the OperatingSystem superclass __init__ method
-            super(LinuxDistro, self).__init__(name, version)
-        else:
-            super().__init__()
-        self.modulecmd = module
-
-    def __str__(self):
-        return self.name + str(self.version)
-
-    @classmethod
-    def _detect_crayos_version(cls):
-        if os.path.isfile(_cle_release_file):
-            release_attrs = read_cle_release_file()
-            if "RELEASE" not in release_attrs:
-                # This Cray system uses a base OS not CLE/CNL
-                return None
-            v = spack.version.Version(release_attrs["RELEASE"])
-            return v[0]
-        elif os.path.isfile(_clerelease_file):
-            v = read_clerelease_file()
-            return spack.version.Version(v)[0]
-        else:
-            # Not all Cray systems run CNL on the backend.
-            # Systems running in what Cray calls "cluster" mode run other
-            # linux OSs under the Cray PE.
-            # So if we don't detect any Cray OS version on the system,
-            # we return None. We can't ever be sure we will get a Cray OS
-            # version.
-            # Returning None allows the calling code to test for the value
-            # being "True-ish" rather than requiring a try/except block.
-            return None
-
-    def arguments_to_detect_version_fn(self, paths):
-        import spack.compilers
-
-        command_arguments = []
-        for compiler_name in spack.compilers.supported_compilers():
-            cmp_cls = spack.compilers.class_for_compiler_name(compiler_name)
-
-            # If the compiler doesn't have a corresponding
-            # Programming Environment, skip to the next
-            if cmp_cls.PrgEnv is None:
-                continue
-
-            if cmp_cls.PrgEnv_compiler is None:
-                tty.die("Must supply PrgEnv_compiler with PrgEnv")
-
-            compiler_id = spack.compilers.CompilerID(self, compiler_name, None)
-            detect_version_args = spack.compilers.DetectVersionArgs(
-                id=compiler_id, variation=(None, None), language="cc", path="cc"
-            )
-            command_arguments.append(detect_version_args)
-        return command_arguments
-
-    def detect_version(self, detect_version_args):
-        import spack.compilers
-
-        modulecmd = self.modulecmd
-        compiler_name = detect_version_args.id.compiler_name
-        compiler_cls = spack.compilers.class_for_compiler_name(compiler_name)
-        output = modulecmd("avail", compiler_cls.PrgEnv_compiler)
-        version_regex = r"({0})/([\d\.]+[\d]-?[\w]*)".format(compiler_cls.PrgEnv_compiler)
-        matches = re.findall(version_regex, output)
-        version = tuple(version for _, version in matches if "classic" not in version)
-        compiler_id = detect_version_args.id
-        value = detect_version_args._replace(id=compiler_id._replace(version=version))
-        return value, None
-
-    def make_compilers(self, compiler_id, paths):
-        import spack.spec
-
-        name = compiler_id.compiler_name
-        cmp_cls = spack.compilers.class_for_compiler_name(name)
-        compilers = []
-        for v in compiler_id.version:
-            comp = cmp_cls(
-                spack.spec.CompilerSpec(name + "@=" + v),
-                self,
-                "any",
-                ["cc", "CC", "ftn"],
-                [cmp_cls.PrgEnv, name + "/" + v],
-            )
-
-            compilers.append(comp)
-        return compilers

lib/spack/spack/operating_systems/cray_frontend.py

@@ -1,105 +0,0 @@
-# Copyright 2013-2024 Lawrence Livermore National Security, LLC and other
-# Spack Project Developers. See the top-level COPYRIGHT file for details.
-#
-# SPDX-License-Identifier: (Apache-2.0 OR MIT)
-
-import contextlib
-import os
-import re
-
-import llnl.util.filesystem as fs
-import llnl.util.lang
-import llnl.util.tty as tty
-
-from spack.util.environment import get_path
-from spack.util.module_cmd import module
-
-from .linux_distro import LinuxDistro
-
-
-@contextlib.contextmanager
-def unload_programming_environment():
-    """Context manager that unloads Cray Programming Environments."""
-    env_bu = None
-
-    # We rely on the fact that the PrgEnv-* modules set the PE_ENV
-    # environment variable.
-    if "PE_ENV" in os.environ:
-        # Copy environment variables to restore them after the compiler
-        # detection. We expect that the only thing PrgEnv-* modules do is
-        # the environment variables modifications.
-        env_bu = os.environ.copy()
-
-        # Get the name of the module from the environment variable.
-        prg_env = "PrgEnv-" + os.environ["PE_ENV"].lower()
-
-        # Unload the PrgEnv-* module. By doing this we intentionally
-        # provoke errors when the Cray's compiler wrappers are executed
-        # (Error: A PrgEnv-* modulefile must be loaded.) so they will not
-        # be detected as valid compilers by the overridden method. We also
-        # expect that the modules that add the actual compilers' binaries
-        # into the PATH environment variable (i.e. the following modules:
-        # 'intel', 'cce', 'gcc', etc.) will also be unloaded since they are
-        # specified as prerequisites in the PrgEnv-* modulefiles.
-        module("unload", prg_env)
-
-    yield
-
-    # Restore the environment.
-    if env_bu is not None:
-        os.environ.clear()
-        os.environ.update(env_bu)
-
-
-class CrayFrontend(LinuxDistro):
-    """Represents OS that runs on login and service nodes of the Cray platform.
-    It acts as a regular Linux without Cray-specific modules and compiler
-    wrappers."""
-
-    @property
-    def compiler_search_paths(self):
-        """Calls the default function but unloads Cray's programming
-        environments first.
-
-        This prevents from detecting Cray compiler wrappers and avoids
-        possible false detections.
-        """
-        import spack.compilers
-
-        with unload_programming_environment():
-            search_paths = get_path("PATH")
-
-        extract_path_re = re.compile(r"prepend-path[\s]*PATH[\s]*([/\w\.:-]*)")
-
-        for compiler_cls in spack.compilers.all_compiler_types():
-            # Check if the compiler class is supported on Cray
-            prg_env = getattr(compiler_cls, "PrgEnv", None)
-            compiler_module = getattr(compiler_cls, "PrgEnv_compiler", None)
-            if not (prg_env and compiler_module):
-                continue
-
-            # It is supported, check which versions are available
-            output = module("avail", compiler_cls.PrgEnv_compiler)
-            version_regex = r"({0})/([\d\.]+[\d]-?[\w]*)".format(compiler_cls.PrgEnv_compiler)
-            matches = re.findall(version_regex, output)
-            versions = tuple(version for _, version in matches if "classic" not in version)
-
-            # Now inspect the modules and add to paths
-            msg = "[CRAY FE] Detected FE compiler [name={0}, versions={1}]"
-            tty.debug(msg.format(compiler_module, versions))
-            for v in versions:
-                try:
-                    current_module = compiler_module + "/" + v
-                    out = module("show", current_module)
-                    match = extract_path_re.search(out)
-                    search_paths += match.group(1).split(":")
-                except Exception as e:
-                    msg = (
-                        "[CRAY FE] An unexpected error occurred while "
-                        "detecting FE compiler [compiler={0}, "
-                        " version={1}, error={2}]"
-                    )
-                    tty.debug(msg.format(compiler_cls.name, v, str(e)))
-
-        search_paths = list(llnl.util.lang.dedupe(search_paths))
-        return fs.search_paths_for_executables(*search_paths)

lib/spack/spack/operating_systems/mac_os.py

@@ -143,6 +143,7 @@ def __init__(self):
             "12": "monterey",
             "13": "ventura",
             "14": "sonoma",
+            "15": "sequoia",
         }
 
         version = macos_version()

lib/spack/spack/package_base.py

@@ -161,7 +161,11 @@ def windows_establish_runtime_linkage(self):
 
         Performs symlinking to incorporate rpath dependencies to Windows runtime search paths
         """
-        if sys.platform == "win32":
+        # If spec is an external, we should not be modifying its bin directory, as we would
+        # be doing in this method
+        # Spack should in general not modify things it has not installed
+        # we can reasonably expect externals to have their link interface properly established
+        if sys.platform == "win32" and not self.spec.external:
             self.win_rpath.add_library_dependent(*self.win_add_library_dependent())
             self.win_rpath.add_rpath(*self.win_add_rpath())
             self.win_rpath.establish_link()
@@ -617,10 +621,6 @@ class PackageBase(WindowsRPath, PackageViewMixin, RedistributionMixin, metaclass
     #: By default do not run tests within package's install()
     run_tests = False
 
-    #: Keep -Werror flags, matches config:flags:keep_werror to override config
-    # NOTE: should be type Optional[Literal['all', 'specific', 'none']] in 3.8+
-    keep_werror: Optional[str] = None
-
     #: Most packages are NOT extendable. Set to True if you want extensions.
     extendable = False
 
@@ -926,6 +926,32 @@ def global_license_file(self):
             self.global_license_dir, self.name, os.path.basename(self.license_files[0])
         )
 
+    # NOTE: return type should be Optional[Literal['all', 'specific', 'none']] in
+    # Python 3.8+, but we still support 3.6.
+    @property
+    def keep_werror(self) -> Optional[str]:
+        """Keep ``-Werror`` flags, matches ``config:flags:keep_werror`` to override config.
+
+        Valid return values are:
+        * ``"all"``: keep all ``-Werror`` flags.
+        * ``"specific"``: keep only ``-Werror=specific-warning`` flags.
+        * ``"none"``: filter out all ``-Werror*`` flags.
+        * ``None``: respect the user's configuration (``"none"`` by default).
+        """
+        if self.spec.satisfies("%nvhpc@:23.3") or self.spec.satisfies("%pgi"):
+            # Filtering works by replacing -Werror with -Wno-error, but older nvhpc and
+            # PGI do not understand -Wno-error, so we disable filtering.
+            return "all"
+
+        elif self.spec.satisfies("%nvhpc@23.4:"):
+            # newer nvhpc supports -Wno-error but can't disable specific warnings with
+            # -Wno-error=warning. Skip -Werror=warning, but still filter -Werror.
+            return "specific"
+
+        else:
+            # use -Werror disablement by default for other compilers
+            return None
+
     @property
     def version(self):
         if not self.spec.versions.concrete:
@@ -1115,10 +1141,9 @@ def _make_stage(self):
             if not link_format:
                 link_format = "build-{arch}-{hash:7}"
             stage_link = self.spec.format_path(link_format)
-            return DevelopStage(compute_stage_name(self.spec), dev_path, stage_link)
-
-        # To fetch the current version
-        source_stage = self._make_root_stage(self.fetcher)
+            source_stage = DevelopStage(compute_stage_name(self.spec), dev_path, stage_link)
+        else:
+            source_stage = self._make_root_stage(self.fetcher)
 
         # all_stages is source + resources + patches
         all_stages = StageComposite()
@@ -1240,7 +1265,7 @@ def install_test_root(self):
         """Return the install test root directory."""
         tty.warn(
             "The 'pkg.install_test_root' property is deprecated with removal "
-            "expected v0.22. Use 'install_test_root(pkg)' instead."
+            "expected v0.23. Use 'install_test_root(pkg)' instead."
         )
         return install_test_root(self)
 
@@ -1447,10 +1472,8 @@ def do_fetch(self, mirror_only=False):
             return
 
         checksum = spack.config.get("config:checksum")
-        fetch = self.stage.needs_fetching
         if (
             checksum
-            and fetch
             and (self.version not in self.versions)
             and (not isinstance(self.version, GitVersion))
         ):
@@ -1557,13 +1580,11 @@ def do_patch(self):
                 tty.debug("Patching failed last time. Restaging.")
                 self.stage.restage()
             else:
-                # develop specs/ DIYStages may have patch failures but
-                # should never be restaged
-                msg = (
-                    "A patch failure was detected in %s." % self.name
-                    + " Build errors may occur due to this."
+                # develop specs may have patch failures but should never be restaged
+                tty.warn(
+                    f"A patch failure was detected in {self.name}."
+                    " Build errors may occur due to this."
                 )
-                tty.warn(msg)
                 return
 
         # If this file exists, then we already applied all the patches.
@@ -1877,7 +1898,10 @@ def do_install(self, **kwargs):
             verbose (bool): Display verbose build output (by default,
                 suppresses it)
         """
-        PackageInstaller([(self, kwargs)]).install()
+        explicit = kwargs.get("explicit", True)
+        if isinstance(explicit, bool):
+            kwargs["explicit"] = {self.spec.dag_hash()} if explicit else set()
+        PackageInstaller([self], kwargs).install()
 
     # TODO (post-34236): Update tests and all packages that use this as a
     # TODO (post-34236): package method to the routine made available to
@@ -1898,7 +1922,7 @@ def cache_extra_test_sources(self, srcs):
         """
         msg = (
             "'pkg.cache_extra_test_sources(srcs) is deprecated with removal "
-            "expected in v0.22. Use 'cache_extra_test_sources(pkg, srcs)' "
+            "expected in v0.23. Use 'cache_extra_test_sources(pkg, srcs)' "
             "instead."
         )
         warnings.warn(msg)
@@ -2446,9 +2470,18 @@ def rpath(self):
 
         # on Windows, libraries of runtime interest are typically
         # stored in the bin directory
+        # Do not include Windows system libraries in the rpath interface
+        # these libraries are handled automatically by VS/VCVARS and adding
+        # Spack derived system libs into the link path or address space of a program
+        # can result in conflicting versions, which makes Spack packages less useable
         if sys.platform == "win32":
             rpaths = [self.prefix.bin]
-            rpaths.extend(d.prefix.bin for d in deps if os.path.isdir(d.prefix.bin))
+            rpaths.extend(
+                d.prefix.bin
+                for d in deps
+                if os.path.isdir(d.prefix.bin)
+                and "windows-system" not in getattr(d.package, "tags", [])
+            )
         else:
             rpaths = [self.prefix.lib, self.prefix.lib64]
             rpaths.extend(d.prefix.lib for d in deps if os.path.isdir(d.prefix.lib))

lib/spack/spack/platforms/__init__.py

@@ -6,7 +6,6 @@
 
 from ._functions import _host, by_name, platforms, prevent_cray_detection, reset
 from ._platform import Platform
-from .cray import Cray
 from .darwin import Darwin
 from .freebsd import FreeBSD
 from .linux import Linux
@@ -15,7 +14,6 @@
 
 __all__ = [
     "Platform",
-    "Cray",
     "Darwin",
     "Linux",
     "FreeBSD",

lib/spack/spack/platforms/_functions.py

@@ -8,7 +8,6 @@
 
 import spack.util.environment
 
-from .cray import Cray
 from .darwin import Darwin
 from .freebsd import FreeBSD
 from .linux import Linux
@@ -16,7 +15,7 @@
 from .windows import Windows
 
 #: List of all the platform classes known to Spack
-platforms = [Cray, Darwin, Linux, Windows, FreeBSD, Test]
+platforms = [Darwin, Linux, Windows, FreeBSD, Test]
 
 
 @llnl.util.lang.memoized

lib/spack/spack/platforms/cray.py

@@ -2,253 +2,10 @@
 # Spack Project Developers. See the top-level COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
-import os
 import os.path
-import platform
-import re
-
-import archspec.cpu
-
-import llnl.util.tty as tty
-
-import spack.target
-import spack.version
-from spack.operating_systems.cray_backend import CrayBackend
-from spack.operating_systems.cray_frontend import CrayFrontend
-from spack.paths import build_env_path
-from spack.util.executable import Executable
-from spack.util.module_cmd import module
-
-from ._platform import NoPlatformError, Platform
-
-_craype_name_to_target_name = {
-    "x86-cascadelake": "cascadelake",
-    "x86-naples": "zen",
-    "x86-rome": "zen2",
-    "x86-milan": "zen3",
-    "x86-skylake": "skylake_avx512",
-    "mic-knl": "mic_knl",
-    "interlagos": "bulldozer",
-    "abudhabi": "piledriver",
-}
-
-_ex_craype_dir = "/opt/cray/pe/cpe"
-_xc_craype_dir = "/opt/cray/pe/cdt"
 
 
 def slingshot_network():
     return os.path.exists("/opt/cray/pe") and (
         os.path.exists("/lib64/libcxi.so") or os.path.exists("/usr/lib64/libcxi.so")
     )
-
-
-def _target_name_from_craype_target_name(name):
-    return _craype_name_to_target_name.get(name, name)
-
-
-class Cray(Platform):
-    priority = 10
-
-    def __init__(self):
-        """Create a Cray system platform.
-
-        Target names should use craype target names but not include the
-        'craype-' prefix. Uses first viable target from:
-          self
-          envars [SPACK_FRONT_END, SPACK_BACK_END]
-          configuration file "targets.yaml" with keys 'front_end', 'back_end'
-          scanning /etc/bash/bashrc.local for back_end only
-        """
-        super().__init__("cray")
-
-        # Make all craype targets available.
-        for target in self._avail_targets():
-            name = _target_name_from_craype_target_name(target)
-            self.add_target(name, spack.target.Target(name, "craype-%s" % target))
-
-        self.back_end = os.environ.get("SPACK_BACK_END", self._default_target_from_env())
-        self.default = self.back_end
-        if self.back_end not in self.targets:
-            # We didn't find a target module for the backend
-            raise NoPlatformError()
-
-        # Setup frontend targets
-        for name in archspec.cpu.TARGETS:
-            if name not in self.targets:
-                self.add_target(name, spack.target.Target(name))
-        self.front_end = os.environ.get("SPACK_FRONT_END", archspec.cpu.host().name)
-        if self.front_end not in self.targets:
-            self.add_target(self.front_end, spack.target.Target(self.front_end))
-
-        front_distro = CrayFrontend()
-        back_distro = CrayBackend()
-
-        self.default_os = str(back_distro)
-        self.back_os = self.default_os
-        self.front_os = str(front_distro)
-
-        self.add_operating_system(self.back_os, back_distro)
-        if self.front_os != self.back_os:
-            self.add_operating_system(self.front_os, front_distro)
-
-    def setup_platform_environment(self, pkg, env):
-        """Change the linker to default dynamic to be more
-        similar to linux/standard linker behavior
-        """
-        # Unload these modules to prevent any silent linking or unnecessary
-        # I/O profiling in the case of darshan.
-        modules_to_unload = ["cray-mpich", "darshan", "cray-libsci", "altd"]
-        for mod in modules_to_unload:
-            module("unload", mod)
-
-        env.set("CRAYPE_LINK_TYPE", "dynamic")
-        cray_wrapper_names = os.path.join(build_env_path, "cray")
-
-        if os.path.isdir(cray_wrapper_names):
-            env.prepend_path("PATH", cray_wrapper_names)
-            env.prepend_path("SPACK_ENV_PATH", cray_wrapper_names)
-
-        # Makes spack installed pkg-config work on Crays
-        env.append_path("PKG_CONFIG_PATH", "/usr/lib64/pkgconfig")
-        env.append_path("PKG_CONFIG_PATH", "/usr/local/lib64/pkgconfig")
-
-        # CRAY_LD_LIBRARY_PATH is used at build time by the cray compiler
-        # wrappers to augment LD_LIBRARY_PATH. This is to avoid long load
-        # times at runtime. This behavior is not always respected on cray
-        # "cluster" systems, so we reproduce it here.
-        if os.environ.get("CRAY_LD_LIBRARY_PATH"):
-            env.prepend_path("LD_LIBRARY_PATH", os.environ["CRAY_LD_LIBRARY_PATH"])
-
-    @classmethod
-    def craype_type_and_version(cls):
-        if os.path.isdir(_ex_craype_dir):
-            craype_dir = _ex_craype_dir
-            craype_type = "EX"
-        elif os.path.isdir(_xc_craype_dir):
-            craype_dir = _xc_craype_dir
-            craype_type = "XC"
-        else:
-            return (None, None)
-
-        # Take the default version from known symlink path
-        default_path = os.path.join(craype_dir, "default")
-        if os.path.islink(default_path):
-            version = spack.version.Version(os.readlink(default_path))
-            return (craype_type, version)
-
-        # If no default version, sort available versions and return latest
-        versions_available = [spack.version.Version(v) for v in os.listdir(craype_dir)]
-        versions_available.sort(reverse=True)
-        if not versions_available:
-            return (craype_type, None)
-        return (craype_type, versions_available[0])
-
-    @classmethod
-    def detect(cls):
-        """
-        Detect whether this system requires CrayPE module support.
-
-        Systems with newer CrayPE (21.10 for EX systems, future work for CS and
-        XC systems) have compilers and MPI wrappers that can be used directly
-        by path. These systems are considered ``linux`` platforms.
-
-        For systems running an older CrayPE, we detect the Cray platform based
-        on the availability through `module` of the Cray programming
-        environment. If this environment is available, we can use it to find
-        compilers, target modules, etc. If the Cray programming environment is
-        not available via modules, then we will treat it as a standard linux
-        system, as the Cray compiler wrappers and other components of the Cray
-        programming environment are irrelevant without module support.
-        """
-        if "opt/cray" not in os.environ.get("MODULEPATH", ""):
-            return False
-
-        craype_type, craype_version = cls.craype_type_and_version()
-        if craype_type == "XC":
-            return True
-        if craype_type == "EX" and craype_version < spack.version.Version("21.10"):
-            return True
-        return False
-
-    def _default_target_from_env(self):
-        """Set and return the default CrayPE target loaded in a clean login
-        session.
-
-        A bash subshell is launched with a wiped environment and the list of
-        loaded modules is parsed for the first acceptable CrayPE target.
-        """
-        # env -i /bin/bash -lc echo $CRAY_CPU_TARGET 2> /dev/null
-        if getattr(self, "default", None) is None:
-            bash = Executable("/bin/bash")
-            output = bash(
-                "--norc",
-                "--noprofile",
-                "-lc",
-                "echo $CRAY_CPU_TARGET",
-                env={"TERM": os.environ.get("TERM", "")},
-                output=str,
-                error=os.devnull,
-            )
-
-            default_from_module = "".join(output.split())  # rm all whitespace
-            if default_from_module:
-                tty.debug("Found default module:%s" % default_from_module)
-                return default_from_module
-            else:
-                front_end = archspec.cpu.host()
-                # Look for the frontend architecture or closest ancestor
-                # available in cray target modules
-                avail = [_target_name_from_craype_target_name(x) for x in self._avail_targets()]
-                for front_end_possibility in [front_end] + front_end.ancestors:
-                    if front_end_possibility.name in avail:
-                        tty.debug("using front-end architecture or available ancestor")
-                        return front_end_possibility.name
-                else:
-                    tty.debug("using platform.machine as default")
-                    return platform.machine()
-
-    def _avail_targets(self):
-        """Return a list of available CrayPE CPU targets."""
-
-        def modules_in_output(output):
-            """Returns a list of valid modules parsed from modulecmd output"""
-            return [i for i in re.split(r"\s\s+|\n", output)]
-
-        def target_names_from_modules(modules):
-            # Craype- module prefixes that are not valid CPU targets.
-            targets = []
-            for mod in modules:
-                if "craype-" in mod:
-                    name = mod[7:]
-                    name = name.split()[0]
-                    _n = name.replace("-", "_")  # test for mic-knl/mic_knl
-                    is_target_name = name in archspec.cpu.TARGETS or _n in archspec.cpu.TARGETS
-                    is_cray_target_name = name in _craype_name_to_target_name
-                    if is_target_name or is_cray_target_name:
-                        targets.append(name)
-
-            return targets
-
-        def modules_from_listdir():
-            craype_default_path = "/opt/cray/pe/craype/default/modulefiles"
-            if os.path.isdir(craype_default_path):
-                return os.listdir(craype_default_path)
-            return []
-
-        if getattr(self, "_craype_targets", None) is None:
-            strategies = [
-                lambda: modules_in_output(module("avail", "-t", "craype-")),
-                modules_from_listdir,
-            ]
-            for available_craype_modules in strategies:
-                craype_modules = available_craype_modules()
-                craype_targets = target_names_from_modules(craype_modules)
-                if craype_targets:
-                    self._craype_targets = craype_targets
-                    break
-            else:
-                # If nothing is found add platform.machine()
-                # to avoid Spack erroring out
-                self._craype_targets = [platform.machine()]
-
-        return self._craype_targets

lib/spack/spack/relocate.py

@@ -16,7 +16,7 @@
 import llnl.util.lang
 import llnl.util.tty as tty
 from llnl.util.lang import memoized
-from llnl.util.symlink import symlink
+from llnl.util.symlink import readlink, symlink
 
 import spack.paths
 import spack.platforms
@@ -25,6 +25,7 @@
 import spack.store
 import spack.util.elf as elf
 import spack.util.executable as executable
+import spack.util.path
 
 from .relocate_text import BinaryFilePrefixReplacer, TextFilePrefixReplacer
 
@@ -565,7 +566,7 @@ def make_link_relative(new_links, orig_links):
         orig_links (list): original links
     """
     for new_link, orig_link in zip(new_links, orig_links):
-        target = os.readlink(orig_link)
+        target = readlink(orig_link)
         relative_target = os.path.relpath(target, os.path.dirname(orig_link))
         os.unlink(new_link)
         symlink(relative_target, new_link)
@@ -613,7 +614,7 @@ def relocate_links(links, prefix_to_prefix):
     """Relocate links to a new install prefix."""
     regex = re.compile("|".join(re.escape(p) for p in prefix_to_prefix.keys()))
     for link in links:
-        old_target = os.readlink(link)
+        old_target = readlink(link)
         match = regex.match(old_target)
 
         # No match.

lib/spack/spack/repo.py

@@ -241,7 +241,7 @@ def get_all_package_diffs(type, rev1="HEAD^1", rev2="HEAD"):
 
     Arguments:
 
-        type (str): String containing one or more of 'A', 'B', 'C'
+        type (str): String containing one or more of 'A', 'R', 'C'
         rev1 (str): Revision to compare against, default is 'HEAD^'
         rev2 (str): Revision to compare to rev1, default is 'HEAD'
 
@@ -264,7 +264,7 @@ def get_all_package_diffs(type, rev1="HEAD^1", rev2="HEAD"):
     lines = [] if not out else re.split(r"\s+", out)
     changed = set()
     for path in lines:
-        pkg_name, _, _ = path.partition(os.sep)
+        pkg_name, _, _ = path.partition("/")
         if pkg_name not in added and pkg_name not in removed:
             changed.add(pkg_name)
 

lib/spack/spack/reporters/cdash.py

@@ -58,7 +58,8 @@
 # Initialize data structures common to each phase's report.
 CDASH_PHASES = set(MAP_PHASES_TO_CDASH.values())
 CDASH_PHASES.add("update")
-
+# CDash request timeout in seconds
+SPACK_CDASH_TIMEOUT = 45
 
 CDashConfiguration = collections.namedtuple(
     "CDashConfiguration", ["upload_url", "packages", "build", "site", "buildstamp", "track"]
@@ -447,7 +448,7 @@ def upload(self, filename):
                 # By default, urllib2 only support GET and POST.
                 # CDash expects this file to be uploaded via PUT.
                 request.get_method = lambda: "PUT"
-                response = opener.open(request)
+                response = opener.open(request, timeout=SPACK_CDASH_TIMEOUT)
                 if self.current_package_name not in self.buildIds:
                     resp_value = response.read()
                     if isinstance(resp_value, bytes):

lib/spack/spack/rewiring.py

@@ -9,7 +9,7 @@
 import tempfile
 from collections import OrderedDict
 
-from llnl.util.symlink import symlink
+from llnl.util.symlink import readlink, symlink
 
 import spack.binary_distribution as bindist
 import spack.error
@@ -26,7 +26,7 @@ def _relocate_spliced_links(links, orig_prefix, new_prefix):
     in our case. This still needs to be called after the copy to destination
     because it expects the new directory structure to be in place."""
     for link in links:
-        link_target = os.readlink(os.path.join(orig_prefix, link))
+        link_target = readlink(os.path.join(orig_prefix, link))
         link_target = re.sub("^" + orig_prefix, new_prefix, link_target)
         new_link_path = os.path.join(new_prefix, link)
         os.unlink(new_link_path)

lib/spack/spack/schema/env.py

@@ -35,6 +35,7 @@
             {
                 "include": {"type": "array", "default": [], "items": {"type": "string"}},
                 "specs": spec_list_schema,
+                "include_concrete": {"type": "array", "default": [], "items": {"type": "string"}},
             },
         ),
     }

lib/spack/spack/schema/packages.py

@@ -141,7 +141,7 @@
                 "deprecatedProperties": {
                     "properties": ["version"],
                     "message": "setting version preferences in the 'all' section of packages.yaml "
-                    "is deprecated and will be removed in v0.22\n\n\tThese preferences "
+                    "is deprecated and will be removed in v0.23\n\n\tThese preferences "
                     "will be ignored by Spack. You can set them only in package-specific sections "
                     "of the same file.\n",
                     "error": False,
@@ -197,7 +197,7 @@
                     "properties": ["target", "compiler", "providers"],
                     "message": "setting 'compiler:', 'target:' or 'provider:' preferences in "
                     "a package-specific section of packages.yaml is deprecated, and will be "
-                    "removed in v0.22.\n\n\tThese preferences will be ignored by Spack, and "
+                    "removed in v0.23.\n\n\tThese preferences will be ignored by Spack, and "
                     "can be set only in the 'all' section of the same file. "
                     "You can run:\n\n\t\t$ spack audit configs\n\n\tto get better diagnostics, "
                     "including files:lines where the deprecated attributes are used.\n\n"

lib/spack/spack/solver/asp.py

@@ -116,6 +116,8 @@ class Provenance(enum.IntEnum):
     PACKAGE_PY = enum.auto()
     # An installed spec
     INSTALLED = enum.auto()
+    # lower provenance for installed git refs so concretizer prefers StandardVersion installs
+    INSTALLED_GIT_VERSION = enum.auto()
     # A runtime injected from another package (e.g. a compiler)
     RUNTIME = enum.auto()
 
@@ -314,6 +316,10 @@ def using_libc_compatibility() -> bool:
     return spack.platforms.host().name == "linux"
 
 
+def c_compiler_runs(compiler: spack.compiler.Compiler) -> bool:
+    return compiler.compiler_verbose_output is not None
+
+
 def extend_flag_list(flag_list, new_flags):
     """Extend a list of flags, preserving order and precedence.
 
@@ -840,8 +846,6 @@ def solve(self, setup, specs, reuse=None, output=None, control=None, allow_depre
         parent_dir = os.path.dirname(__file__)
         self.control.load(os.path.join(parent_dir, "concretize.lp"))
         self.control.load(os.path.join(parent_dir, "heuristic.lp"))
-        if spack.config.CONFIG.get("concretizer:duplicates:strategy", "none") != "none":
-            self.control.load(os.path.join(parent_dir, "heuristic_separate.lp"))
         self.control.load(os.path.join(parent_dir, "display.lp"))
         if not setup.concretize_everything:
             self.control.load(os.path.join(parent_dir, "when_possible.lp"))
@@ -1649,11 +1653,15 @@ def external_packages(self):
         if isinstance(reuse_yaml, typing.Mapping):
             default_include = reuse_yaml.get("include", [])
             default_exclude = reuse_yaml.get("exclude", [])
+            libc_externals = list(all_libcs())
             for source in reuse_yaml.get("from", []):
                 if source["type"] != "external":
                     continue
 
                 include = source.get("include", default_include)
+                if include:
+                    # Since libcs are implicit externals, we need to implicitly include them
+                    include = include + libc_externals
                 exclude = source.get("exclude", default_exclude)
                 spec_filters.append(
                     SpecFilter(
@@ -1872,11 +1880,8 @@ def _spec_clauses(
                             )
 
                 clauses.append(f.variant_value(spec.name, vname, value))
-
                 if variant.propagate:
-                    clauses.append(
-                        f.variant_propagation_candidate(spec.name, vname, value, spec.name)
-                    )
+                    clauses.append(f.propagate(spec.name, fn.variant_value(vname, value)))
 
                 # Tell the concretizer that this is a possible value for the
                 # variant, to account for things like int/str values where we
@@ -1909,9 +1914,12 @@ def _spec_clauses(
         for flag_type, flags in spec.compiler_flags.items():
             for flag in flags:
                 clauses.append(f.node_flag(spec.name, flag_type, flag))
-                clauses.append(f.node_flag_source(spec.name, flag_type, spec.name))
                 if not spec.concrete and flag.propagate is True:
-                    clauses.append(f.node_flag_propagate(spec.name, flag_type))
+                    clauses.append(
+                        f.propagate(
+                            spec.name, fn.node_flag(flag_type, flag), fn.edge_types("link", "run")
+                        )
+                    )
 
         # dependencies
         if spec.concrete:
@@ -1931,6 +1939,11 @@ def _spec_clauses(
             for virtual in virtuals:
                 clauses.append(fn.attr("virtual_on_incoming_edges", spec.name, virtual))
 
+        # If the spec is external and concrete, we allow all the libcs on the system
+        if spec.external and spec.concrete and using_libc_compatibility():
+            for libc in self.libcs:
+                clauses.append(fn.attr("compatible_libc", spec.name, libc.name, libc.version))
+
         # add all clauses from dependencies
         if transitive:
             # TODO: Eventually distinguish 2 deps on the same pkg (build and link)
@@ -2059,7 +2072,7 @@ def define_ad_hoc_versions_from_specs(
             # best possible, so they're guaranteed to be used preferentially.
             version = s.versions.concrete
 
-            if version is None or any(v == version for v in self.possible_versions[s.name]):
+            if version is None or (any((v == version) for v in self.possible_versions[s.name])):
                 continue
 
             if require_checksum and not _is_checksummed_git_version(version):
@@ -2373,9 +2386,16 @@ def concrete_specs(self):
             # - Add OS to possible OS's
             for dep in spec.traverse():
                 self.possible_versions[dep.name].add(dep.version)
-                self.declared_versions[dep.name].append(
-                    DeclaredVersion(version=dep.version, idx=0, origin=Provenance.INSTALLED)
-                )
+                if isinstance(dep.version, vn.GitVersion):
+                    self.declared_versions[dep.name].append(
+                        DeclaredVersion(
+                            version=dep.version, idx=0, origin=Provenance.INSTALLED_GIT_VERSION
+                        )
+                    )
+                else:
+                    self.declared_versions[dep.name].append(
+                        DeclaredVersion(version=dep.version, idx=0, origin=Provenance.INSTALLED)
+                    )
                 self.possible_oses.add(dep.os)
 
     def define_concrete_input_specs(self, specs, possible):
@@ -2427,7 +2447,7 @@ def setup(
 
         if using_libc_compatibility():
             for libc in self.libcs:
-                self.gen.fact(fn.allowed_libc(libc.name, libc.version))
+                self.gen.fact(fn.host_libc(libc.name, libc.version))
 
         if not allow_deprecated:
             self.gen.fact(fn.deprecated_versions_not_allowed())
@@ -2724,9 +2744,7 @@ class _Head:
     node_compiler = fn.attr("node_compiler_set")
     node_compiler_version = fn.attr("node_compiler_version_set")
     node_flag = fn.attr("node_flag_set")
-    node_flag_source = fn.attr("node_flag_source")
-    node_flag_propagate = fn.attr("node_flag_propagate")
-    variant_propagation_candidate = fn.attr("variant_propagation_candidate")
+    propagate = fn.attr("propagate")
 
 
 class _Body:
@@ -2741,9 +2759,7 @@ class _Body:
     node_compiler = fn.attr("node_compiler")
     node_compiler_version = fn.attr("node_compiler_version")
     node_flag = fn.attr("node_flag")
-    node_flag_source = fn.attr("node_flag_source")
-    node_flag_propagate = fn.attr("node_flag_propagate")
-    variant_propagation_candidate = fn.attr("variant_propagation_candidate")
+    propagate = fn.attr("propagate")
 
 
 class ProblemInstanceBuilder:
@@ -2971,6 +2987,13 @@ class CompilerParser:
     def __init__(self, configuration) -> None:
         self.compilers: Set[KnownCompiler] = set()
         for c in all_compilers_in_config(configuration):
+            if using_libc_compatibility() and not c_compiler_runs(c):
+                tty.debug(
+                    f"the C compiler {c.cc} does not exist, or does not run correctly."
+                    f" The compiler {c.spec} will not be used during concretization."
+                )
+                continue
+
             if using_libc_compatibility() and not c.default_libc:
                 warnings.warn(
                     f"cannot detect libc from {c.spec}. The compiler will not be used "
@@ -3210,6 +3233,39 @@ def requires(self, impose: str, *, when: str):
         self.runtime_conditions.add((imposed_spec, when_spec))
         self.reset()
 
+    def propagate(self, constraint_str: str, *, when: str):
+        msg = "the 'propagate' method can be called only with pkg('*')"
+        assert self.current_package == "*", msg
+
+        when_spec = spack.spec.Spec(when)
+        assert when_spec.name is None, "only anonymous when specs are accepted"
+
+        placeholder = "XXX"
+        node_variable = "node(ID, Package)"
+        when_spec.name = placeholder
+
+        body_clauses = self._setup.spec_clauses(when_spec, body=True)
+        body_str = (
+            f"  {f',{os.linesep}  '.join(str(x) for x in body_clauses)},\n"
+            f"  not external({node_variable}),\n"
+            f"  not runtime(Package)"
+        ).replace(f'"{placeholder}"', f"{node_variable}")
+
+        constraint_spec = spack.spec.Spec(constraint_str)
+        assert constraint_spec.name is None, "only anonymous constraint specs are accepted"
+
+        constraint_spec.name = placeholder
+        constraint_clauses = self._setup.spec_clauses(constraint_spec, body=False)
+        for clause in constraint_clauses:
+            if clause.args[0] == "node_compiler_version_satisfies":
+                self._setup.compiler_version_constraints.add(constraint_spec.compiler)
+                args = f'"{constraint_spec.compiler.name}", "{constraint_spec.compiler.versions}"'
+                head_str = f"propagate({node_variable}, node_compiler_version_satisfies({args}))"
+                rule = f"{head_str} :-\n{body_str}.\n\n"
+                self.rules.append(rule)
+
+        self.reset()
+
     def consume_facts(self):
         """Consume the facts collected by this object, and emits rules and
         facts for the runtimes.
@@ -3289,6 +3345,8 @@ def hash(self, node, h):
     def node(self, node):
         if node not in self._specs:
             self._specs[node] = spack.spec.Spec(node.pkg)
+            for flag_type in spack.spec.FlagMap.valid_compiler_flags():
+                self._specs[node].compiler_flags[flag_type] = []
 
     def _arch(self, node):
         arch = self._specs[node].architecture
@@ -3341,9 +3399,6 @@ def node_flag(self, node, flag_type, flag):
     def node_flag_source(self, node, flag_type, source):
         self._flag_sources[(node, flag_type)].add(source)
 
-    def no_flags(self, node, flag_type):
-        self._specs[node].compiler_flags[flag_type] = []
-
     def external_spec_selected(self, node, idx):
         """This means that the external spec and index idx has been selected for this package."""
         packages_yaml = _external_config_with_implicit_externals(spack.config.CONFIG)
@@ -3436,7 +3491,7 @@ def reorder_flags(self):
                 ordered_compiler_flags = list(llnl.util.lang.dedupe(from_compiler + from_sources))
                 compiler_flags = spec.compiler_flags.get(flag_type, [])
 
-                msg = "%s does not equal %s" % (set(compiler_flags), set(ordered_compiler_flags))
+                msg = f"{set(compiler_flags)} does not equal {set(ordered_compiler_flags)}"
                 assert set(compiler_flags) == set(ordered_compiler_flags), msg
 
                 spec.compiler_flags.update({flag_type: ordered_compiler_flags})
@@ -3506,9 +3561,8 @@ def build_specs(self, function_tuples):
                 # do not bother calling actions on it except for node_flag_source,
                 # since node_flag_source is tracking information not in the spec itself
                 spec = self._specs.get(args[0])
-                if spec and spec.concrete:
-                    if name != "node_flag_source":
-                        continue
+                if spec and spec.concrete and name != "node_flag_source":
+                    continue
 
             action(*args)
 
@@ -3779,12 +3833,6 @@ class Solver:
     def __init__(self):
         self.driver = PyclingoDriver()
         self.selector = ReusableSpecsSelector(configuration=spack.config.CONFIG)
-        if spack.platforms.host().name == "cray":
-            msg = (
-                "The Cray platform, i.e. 'platform=cray', will be removed in Spack v0.23. "
-                "All Cray machines will be then detected as 'platform=linux'."
-            )
-            warnings.warn(msg)
 
     @staticmethod
     def _check_input_and_extract_concrete_specs(specs):

lib/spack/spack/solver/concretize.lp

@@ -29,7 +29,6 @@
 :- attr("variant_value", PackageNode, _, _), not attr("node", PackageNode).
 :- attr("node_flag_compiler_default", PackageNode), not attr("node", PackageNode).
 :- attr("node_flag", PackageNode, _, _), not attr("node", PackageNode).
-:- attr("no_flags", PackageNode, _), not attr("node", PackageNode).
 :- attr("external_spec_selected", PackageNode, _), not attr("node", PackageNode).
 :- attr("depends_on", ParentNode, _, _), not attr("node", ParentNode).
 :- attr("depends_on", _, ChildNode, _), not attr("node", ChildNode).
@@ -256,6 +255,7 @@ possible_version_weight(node(ID, Package), Weight)
 :- attr("version", node(ID, Package), Version),
    version_weight(node(ID, Package), Weight),
    not pkg_fact(Package, version_declared(Version, Weight, "installed")),
+   not pkg_fact(Package, version_declared(Version, Weight, "installed_git_version")),
    not build(node(ID, Package)),
    internal_error("Build version weight used for reused package").
 
@@ -811,37 +811,6 @@ node_has_variant(node(ID, Package), Variant) :-
   pkg_fact(Package, variant(Variant)),
   attr("node", node(ID, Package)).
 
-% Variant propagation is forwarded to dependencies
-attr("variant_propagation_candidate", PackageNode, Variant, Value, Source) :-
-  attr("node", PackageNode),
-  depends_on(ParentNode, PackageNode),
-  attr("variant_value", node(_, Source), Variant, Value),
-  attr("variant_propagation_candidate", ParentNode, Variant, _, Source).
-
-% If the node is a candidate, and it has the variant and value,
-% then those variant and value should be propagated
-attr("variant_propagate", node(ID, Package), Variant, Value, Source) :-
-  attr("variant_propagation_candidate", node(ID, Package), Variant, Value, Source),
-  node_has_variant(node(ID, Package), Variant),
-  pkg_fact(Package, variant_possible_value(Variant, Value)),
-  not attr("variant_set", node(ID, Package), Variant).
-
-% Propagate the value, if there is the corresponding attribute
-attr("variant_value", PackageNode, Variant, Value) :- attr("variant_propagate", PackageNode, Variant, Value, _).
-
-% If a variant is propagated, we cannot have extraneous values (this is for multi valued variants)
-variant_is_propagated(PackageNode, Variant) :- attr("variant_propagate", PackageNode, Variant, _, _).
-:- variant_is_propagated(PackageNode, Variant),
-   attr("variant_value", PackageNode, Variant, Value),
-   not attr("variant_propagate", PackageNode, Variant, Value, _).
-
-% Cannot receive different values from different sources on the same variant
-error(100, "{0} and {1} cannot both propagate variant '{2}' to package {3} with values '{4}' and '{5}'", Source1, Source2, Variant, Package, Value1, Value2) :-
-  attr("variant_propagate", node(X, Package), Variant, Value1, Source1),
-  attr("variant_propagate", node(X, Package), Variant, Value2, Source2),
-  node_has_variant(node(X, Package), Variant),
-  Value1 < Value2, Source1 < Source2.
-
 % a variant cannot be set if it is not a variant on the package
 error(100, "Cannot set variant '{0}' for package '{1}' because the variant condition cannot be satisfied for the given spec", Variant, Package)
   :- attr("variant_set", node(X, Package), Variant),
@@ -919,7 +888,7 @@ variant_not_default(node(ID, Package), Variant, Value)
     % variants set explicitly on the CLI don't count as non-default
     not attr("variant_set", node(ID, Package), Variant, Value),
     % variant values forced by propagation don't count as non-default
-    not attr("variant_propagate", node(ID, Package), Variant, Value, _),
+    not propagate(node(ID, Package), variant_value(Variant, Value)),
     % variants set on externals that we could use don't count as non-default
     % this makes spack prefer to use an external over rebuilding with the
     % default configuration
@@ -932,7 +901,7 @@ variant_default_not_used(node(ID, Package), Variant, Value)
   :- variant_default_value(Package, Variant, Value),
      node_has_variant(node(ID, Package), Variant),
      not attr("variant_value", node(ID, Package), Variant, Value),
-     not attr("variant_propagate", node(ID, Package), Variant, _, _),
+     not propagate(node(ID, Package), variant_value(Variant, _)),
      attr("node", node(ID, Package)).
 
 % The variant is set in an external spec
@@ -989,6 +958,101 @@ pkg_fact(Package, variant_single_value("dev_path"))
 #defined variant_default_value/3.
 #defined variant_default_value_from_packages_yaml/3.
 
+%-----------------------------------------------------------------------------
+% Propagation semantics
+%-----------------------------------------------------------------------------
+
+% Propagation roots have a corresponding attr("propagate", ...)
+propagate(RootNode, PropagatedAttribute) :- attr("propagate", RootNode, PropagatedAttribute).
+propagate(RootNode, PropagatedAttribute, EdgeTypes) :- attr("propagate", RootNode, PropagatedAttribute, EdgeTypes).
+
+
+% Propagate an attribute along edges to child nodes
+propagate(ChildNode, PropagatedAttribute) :-
+  propagate(ParentNode, PropagatedAttribute),
+  depends_on(ParentNode, ChildNode).
+
+propagate(ChildNode, PropagatedAttribute, edge_types(DepType1, DepType2)) :-
+  propagate(ParentNode, PropagatedAttribute, edge_types(DepType1, DepType2)),
+  depends_on(ParentNode, ChildNode),
+  1 { attr("depends_on", ParentNode, ChildNode, DepType1);  attr("depends_on", ParentNode, ChildNode, DepType2) }.
+
+%-----------------------------------------------------------------------------
+% Activation of propagated values
+%-----------------------------------------------------------------------------
+
+%----
+% Variants
+%----
+
+% If a variant is propagated, and can be accepted, set its value
+attr("variant_value", node(ID, Package), Variant, Value) :-
+  propagate(node(ID, Package), variant_value(Variant, Value)),
+  node_has_variant(node(ID, Package), Variant),
+  pkg_fact(Package, variant_possible_value(Variant, Value)),
+  not attr("variant_set", node(ID, Package), Variant).
+
+% If a variant is propagated, we cannot have extraneous values
+variant_is_propagated(PackageNode, Variant) :-
+  attr("variant_value", PackageNode, Variant, Value),
+  propagate(PackageNode, variant_value(Variant, Value)),
+  not attr("variant_set", PackageNode, Variant).
+
+:- variant_is_propagated(PackageNode, Variant),
+   attr("variant_value", PackageNode, Variant, Value),
+   not propagate(PackageNode, variant_value(Variant, Value)).
+
+%----
+% Flags
+%----
+
+% A propagated flag implies:
+% 1. The same flag type is not set on this node
+% 2. This node has the same compiler as the propagation source
+
+propagated_flag(node(PackageID, Package), node_flag(FlagType, Flag), SourceNode) :-
+  propagate(node(PackageID, Package), node_flag(FlagType, Flag), _),
+  not attr("node_flag_set", node(PackageID, Package), FlagType, _),
+  % Same compiler as propagation source
+  node_compiler(node(PackageID, Package), CompilerID),
+  node_compiler(SourceNode, CompilerID),
+  attr("propagate", SourceNode, node_flag(FlagType, Flag), _),
+  node(PackageID, Package) != SourceNode,
+  not runtime(Package).
+
+attr("node_flag", PackageNode, FlagType, Flag) :- propagated_flag(PackageNode, node_flag(FlagType, Flag), _).
+attr("node_flag_source", PackageNode, FlagType, SourceNode) :- propagated_flag(PackageNode, node_flag(FlagType, _), SourceNode).
+
+% Cannot propagate the same flag from two distinct sources
+error(100, "{0} and {1} cannot both propagate compiler flags '{2}' to {3}", Source1, Source2, Package, FlagType) :-
+  propagated_flag(node(ID, Package), node_flag(FlagType, _), node(_, Source1)),
+  propagated_flag(node(ID, Package), node_flag(FlagType, _), node(_, Source2)),
+  Source1 < Source2.
+
+%----
+% Compiler constraints
+%----
+
+attr("node_compiler_version_satisfies", node(ID, Package), Compiler, Version) :-
+  propagate(node(ID, Package), node_compiler_version_satisfies(Compiler, Version)),
+  node_compiler(node(ID, Package), CompilerID),
+  compiler_name(CompilerID, Compiler),
+  not runtime(Package),
+  not external(Package).
+
+%-----------------------------------------------------------------------------
+% Runtimes
+%-----------------------------------------------------------------------------
+
+% Check whether the DAG has any built package
+has_built_packages() :- build(X), not external(X).
+
+% If we build packages, the runtime nodes must use an available compiler
+1 { node_compiler(PackageNode, CompilerID) : build(PackageNode), not external(PackageNode) } :-
+  has_built_packages(),
+  runtime(RuntimePackage),
+  node_compiler(node(_, RuntimePackage), CompilerID).
+
 %-----------------------------------------------------------------------------
 % Platform semantics
 %-----------------------------------------------------------------------------
@@ -1090,10 +1154,15 @@ attr("node_target", PackageNode, Target)
  :- attr("node", PackageNode), attr("node_target_set", PackageNode, Target).
 
 % each node has the weight of its assigned target
-node_target_weight(node(ID, Package), Weight)
- :- attr("node", node(ID, Package)),
-    attr("node_target", node(ID, Package), Target),
-    target_weight(Target, Weight).
+target_weight(Target, 0)
+ :- attr("node", PackageNode),
+    attr("node_target", PackageNode, Target),
+    attr("node_target_set", PackageNode, Target).
+
+node_target_weight(PackageNode, MinWeight)
+ :- attr("node", PackageNode),
+    attr("node_target", PackageNode, Target),
+    MinWeight = #min { Weight : target_weight(Target, Weight) }.
 
 % compatibility rules for targets among nodes
 node_target_match(ParentNode, DependencyNode)
@@ -1155,12 +1224,12 @@ error(10, "No valid compiler for {0} satisfies '%{1}'", Package, Compiler)
 
 % If the compiler of a node must satisfy a constraint, then its version
 % must be chosen among the ones that satisfy said constraint
-error(100, "No valid version for '{0}' compiler '{1}' satisfies '@{2}'", Package, Compiler, Constraint)
+error(100, "Package {0} cannot satisfy '%{1}@{2}'", Package, Compiler, Constraint)
   :- attr("node", node(X, Package)),
      attr("node_compiler_version_satisfies", node(X, Package), Compiler, Constraint),
-		 not compiler_version_satisfies(Compiler, Constraint, _).
+	 not compiler_version_satisfies(Compiler, Constraint, _).
 
-error(100, "No valid version for '{0}' compiler '{1}' satisfies '@{2}'", Package, Compiler, Constraint)
+error(100, "Package {0} cannot satisfy '%{1}@{2}'", Package, Compiler, Constraint)
   :- attr("node", node(X, Package)),
      attr("node_compiler_version_satisfies", node(X, Package), Compiler, Constraint),
      not compiler_version_satisfies(Compiler, Constraint, ID),
@@ -1241,45 +1310,9 @@ error(100, "Compiler {1}@{2} requested for {0} cannot be found. Set install_miss
 % Compiler flags
 %-----------------------------------------------------------------------------
 
-% propagate flags when compiler match
-can_inherit_flags(PackageNode, DependencyNode, FlagType)
-  :- same_compiler(PackageNode, DependencyNode),
-     not attr("node_flag_set", DependencyNode, FlagType, _),
-     flag_type(FlagType).
-
-same_compiler(PackageNode, DependencyNode)
-  :- depends_on(PackageNode, DependencyNode),
-     node_compiler(PackageNode, CompilerID),
-     node_compiler(DependencyNode, CompilerID),
-     compiler_id(CompilerID).
-
-node_flag_inherited(DependencyNode, FlagType, Flag)
-  :- attr("node_flag_set", PackageNode, FlagType, Flag),
-     can_inherit_flags(PackageNode, DependencyNode, FlagType),
-     attr("node_flag_propagate", PackageNode, FlagType).
-
-% Ensure propagation
-:- node_flag_inherited(PackageNode, FlagType, Flag),
-   can_inherit_flags(PackageNode, DependencyNode, FlagType),
-   attr("node_flag_propagate", PackageNode, FlagType).
-
-error(100, "{0} and {1} cannot both propagate compiler flags '{2}' to {3}", Source1, Source2, Package, FlagType) :-
-  depends_on(Source1, Package),
-  depends_on(Source2, Package),
-  attr("node_flag_propagate", Source1, FlagType),
-  attr("node_flag_propagate", Source2, FlagType),
-  can_inherit_flags(Source1, Package, FlagType),
-  can_inherit_flags(Source2, Package, FlagType),
-  Source1 < Source2.
-
 % remember where flags came from
-attr("node_flag_source", PackageNode, FlagType, PackageNode)
-  :- attr("node_flag_set", PackageNode, FlagType, _).
-
-attr("node_flag_source", DependencyNode, FlagType, Q)
-  :- attr("node_flag_source", PackageNode, FlagType, Q),
-     node_flag_inherited(DependencyNode, FlagType, _),
-     attr("node_flag_propagate", PackageNode, FlagType).
+attr("node_flag_source", PackageNode, FlagType, PackageNode) :- attr("node_flag_set", PackageNode, FlagType, _).
+attr("node_flag_source", PackageNode, FlagType, PackageNode) :- attr("node_flag", PackageNode, FlagType, _), attr("hash", PackageNode, _).
 
 % compiler flags from compilers.yaml are put on nodes if compiler matches
 attr("node_flag", PackageNode, FlagType, Flag)
@@ -1299,15 +1332,8 @@ attr("node_flag_compiler_default", PackageNode)
      compiler_name(CompilerID, CompilerName),
      compiler_version(CompilerID, Version).
 
-% if a flag is set to something or inherited, it's included
+% Flag set to something
 attr("node_flag", PackageNode, FlagType, Flag) :- attr("node_flag_set", PackageNode, FlagType, Flag).
-attr("node_flag", PackageNode, FlagType, Flag) :- node_flag_inherited(PackageNode, FlagType, Flag).
-
-% if no node flags are set for a type, there are no flags.
-attr("no_flags", PackageNode, FlagType)
-  :- not attr("node_flag", PackageNode, FlagType, _),
-     attr("node", PackageNode),
-     flag_type(FlagType).
 
 #defined compiler_flag/3.
 
@@ -1345,8 +1371,10 @@ build(PackageNode) :- not attr("hash", PackageNode, _), attr("node", PackageNode
 % topmost-priority criterion to reuse what is installed.
 %
 % The priority ranges are:
-%   200+        Shifted priorities for build nodes; correspond to priorities 0 - 99.
-%   100 - 199   Unshifted priorities. Currently only includes minimizing #builds.
+%   1000+       Optimizations for concretization errors
+%   300 - 1000  Highest priority optimizations for valid solutions
+%   200 - 299   Shifted priorities for build nodes; correspond to priorities 0 - 99.
+%   100 - 199   Unshifted priorities. Currently only includes minimizing #builds and minimizing dupes.
 %   0   -  99   Priorities for non-built nodes.
 build_priority(PackageNode, 200) :- build(PackageNode), attr("node", PackageNode).
 build_priority(PackageNode, 0)   :- not build(PackageNode), attr("node", PackageNode).
@@ -1394,6 +1422,16 @@ build_priority(PackageNode, 0)   :- not build(PackageNode), attr("node", Package
 %   2. a `#minimize{ 0@2 : #true }.` statement that ensures the criterion
 %      is displayed (clingo doesn't display sums over empty sets by default)
 
+% A condition group specifies one or more specs that must be satisfied.
+% Specs declared first are preferred, so we assign increasing weights and
+% minimize the weights.
+opt_criterion(310, "requirement weight").
+#minimize{ 0@310: #true }.
+#minimize {
+    Weight@310,PackageNode,Group
+    : requirement_weight(PackageNode, Group, Weight)
+}.
+
 % Try hard to reuse installed packages (i.e., minimize the number built)
 opt_criterion(110, "number of packages to build (vs. reuse)").
 #minimize { 0@110: #true }.
@@ -1405,18 +1443,6 @@ opt_criterion(100, "number of nodes from the same package").
 #minimize { ID@100,Package : attr("virtual_node", node(ID, Package)) }.
 #defined optimize_for_reuse/0.
 
-% A condition group specifies one or more specs that must be satisfied.
-% Specs declared first are preferred, so we assign increasing weights and
-% minimize the weights.
-opt_criterion(75, "requirement weight").
-#minimize{ 0@275: #true }.
-#minimize{ 0@75: #true }.
-#minimize {
-    Weight@75+Priority,PackageNode,Group
-    : requirement_weight(PackageNode, Group, Weight),
-      build_priority(PackageNode, Priority)
-}.
-
 % Minimize the number of deprecated versions being used
 opt_criterion(73, "deprecated versions used").
 #minimize{ 0@273: #true }.
@@ -1424,6 +1450,7 @@ opt_criterion(73, "deprecated versions used").
 #minimize{
     1@73+Priority,PackageNode
     : attr("deprecated", PackageNode, _),
+      not external(PackageNode),
       build_priority(PackageNode, Priority)
 }.
 
@@ -1431,11 +1458,11 @@ opt_criterion(73, "deprecated versions used").
 % 1. Version weight
 % 2. Number of variants with a non default value, if not set
 % for the root package.
-opt_criterion(70, "version weight").
+opt_criterion(70, "version badness (roots)").
 #minimize{ 0@270: #true }.
 #minimize{ 0@70: #true }.
 #minimize {
-    Weight@70+Priority
+    Weight@70+Priority,PackageNode
     : attr("root", PackageNode),
       version_weight(PackageNode, Weight),
       build_priority(PackageNode, Priority)
@@ -1495,7 +1522,7 @@ opt_criterion(45, "preferred providers (non-roots)").
 }.
 
 % Try to minimize the number of compiler mismatches in the DAG.
-opt_criterion(40, "compiler mismatches that are not from CLI").
+opt_criterion(40, "compiler mismatches that are not required").
 #minimize{ 0@240: #true }.
 #minimize{ 0@40: #true }.
 #minimize{
@@ -1505,7 +1532,7 @@ opt_criterion(40, "compiler mismatches that are not from CLI").
       not runtime(Dependency)
 }.
 
-opt_criterion(39, "compiler mismatches that are not from CLI").
+opt_criterion(39, "compiler mismatches that are required").
 #minimize{ 0@239: #true }.
 #minimize{ 0@39: #true }.
 #minimize{
@@ -1525,13 +1552,14 @@ opt_criterion(30, "non-preferred OS's").
 }.
 
 % Choose more recent versions for nodes
-opt_criterion(25, "version badness").
+opt_criterion(25, "version badness (non roots)").
 #minimize{ 0@225: #true }.
 #minimize{ 0@25: #true }.
 #minimize{
     Weight@25+Priority,node(X, Package)
     : version_weight(node(X, Package), Weight),
       build_priority(node(X, Package), Priority),
+      not attr("root", node(X, Package)),
       not runtime(Package)
 }.
 

lib/spack/spack/solver/heuristic.lp

@@ -4,21 +4,35 @@
 % SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 %=============================================================================
-% Heuristic to speed-up solves (node with ID 0)
+% Heuristic to speed-up solves
 %=============================================================================
 
+% No duplicates by default (most of them will be true)
+#heuristic attr("node",         node(PackageID, Package)). [100, init]
+#heuristic attr("node",         node(PackageID, Package)). [  2, factor]
+#heuristic attr("virtual_node", node(VirtualID, Virtual)). [100, init]
+#heuristic attr("node",         node(1..X-1, Package)) : max_dupes(Package, X), not virtual(Package), X > 1. [-1, sign]
+#heuristic attr("virtual_node", node(1..X-1, Package)) : max_dupes(Package, X), virtual(Package)    , X > 1. [-1, sign]
 
-%-----------------
-% Domain heuristic
-%-----------------
+% Pick preferred version
+#heuristic attr("version", node(PackageID, Package), Version) : pkg_fact(Package, version_declared(Version, Weight)), attr("node", node(PackageID, Package)).             [40, init]
+#heuristic version_weight(node(PackageID, Package), 0)        : pkg_fact(Package, version_declared(Version, 0     )), attr("node", node(PackageID, Package)).             [ 1, sign]
+#heuristic attr("version", node(PackageID, Package), Version) : pkg_fact(Package, version_declared(Version, 0     )), attr("node", node(PackageID, Package)).             [ 1, sign]
+#heuristic attr("version", node(PackageID, Package), Version) : pkg_fact(Package, version_declared(Version, Weight)), attr("node", node(PackageID, Package)), Weight > 0. [-1, sign]
 
-% Root node
-#heuristic attr("version", node(0, Package), Version) : pkg_fact(Package, version_declared(Version, 0)), attr("root", node(0, Package)). [35, true]
-#heuristic version_weight(node(0, Package), 0) : pkg_fact(Package, version_declared(Version, 0)), attr("root", node(0, Package)). [35, true]
-#heuristic attr("variant_value", node(0, Package), Variant, Value) : variant_default_value(Package, Variant, Value), attr("root", node(0, Package)). [35, true]
-#heuristic attr("node_target", node(0, Package), Target) : target_weight(Target, 0), attr("root", node(0, Package)). [35, true]
-#heuristic node_target_weight(node(0, Package), 0) : attr("root", node(0, Package)). [35, true]
-#heuristic node_compiler(node(0, Package), CompilerID) : compiler_weight(ID, 0), compiler_id(ID), attr("root", node(0, Package)). [35, true]
+% Use default variants
+#heuristic attr("variant_value", node(PackageID, Package), Variant, Value) : variant_default_value(Package, Variant, Value),     attr("node", node(PackageID, Package)). [40, true]
+#heuristic attr("variant_value", node(PackageID, Package), Variant, Value) : not variant_default_value(Package, Variant, Value), attr("node", node(PackageID, Package)). [40, false]
 
-% Providers
-#heuristic attr("node", node(0, Package)) : default_provider_preference(Virtual, Package, 0), possible_in_link_run(Package). [30, true]
+% Use default operating system and platform
+#heuristic attr("node_os", node(PackageID, Package), OS) : os(OS, 0), attr("root", node(PackageID, Package)). [40, true]
+#heuristic attr("node_platform", node(PackageID, Package), Platform) : allowed_platform(Platform), attr("root", node(PackageID, Package)). [40, true]
+
+% Use default targets
+#heuristic attr("node_target", node(PackageID, Package), Target) : target_weight(Target, Weight), attr("node", node(PackageID, Package)). [30, init]
+#heuristic attr("node_target", node(PackageID, Package), Target) : target_weight(Target, Weight), attr("node", node(PackageID, Package)). [ 2, factor]
+#heuristic attr("node_target", node(PackageID, Package), Target) : target_weight(Target,      0), attr("node", node(PackageID, Package)). [ 1, sign]
+#heuristic attr("node_target", node(PackageID, Package), Target) : target_weight(Target, Weight), attr("node", node(PackageID, Package)), Weight > 0. [-1, sign]
+
+% Use the default compilers
+#heuristic node_compiler(node(PackageID, Package), ID) : compiler_weight(ID, 0), compiler_id(ID), attr("node", node(PackageID, Package)). [30, init]

lib/spack/spack/solver/heuristic_separate.lp

@@ -1,24 +0,0 @@
-% Copyright 2013-2024 Lawrence Livermore National Security, LLC and other
-% Spack Project Developers. See the top-level COPYRIGHT file for details.
-%
-% SPDX-License-Identifier: (Apache-2.0 OR MIT)
-
-%=============================================================================
-% Heuristic to speed-up solves (node with ID > 0)
-%=============================================================================
-
-% node(ID, _)
-#heuristic attr("version", node(ID, Package), Version) : pkg_fact(Package, version_declared(Version, 0)), attr("node", node(ID, Package)), ID > 0. [25-5*ID, true]
-#heuristic version_weight(node(ID, Package), 0) : pkg_fact(Package, version_declared(Version, 0)), attr("node", node(ID, Package)), ID > 0. [25-5*ID, true]
-#heuristic attr("variant_value", node(ID, Package), Variant, Value) : variant_default_value(Package, Variant, Value), attr("node", node(ID, Package)), ID > 0. [25-5*ID, true]
-#heuristic attr("node_target", node(ID, Package), Target) : pkg_fact(Package, target_weight(Target, 0)), attr("node", node(ID, Package)), ID > 0. [25-5*ID, true]
-#heuristic node_target_weight(node(ID, Package), 0) : attr("node", node(ID, Package)), ID > 0. [25-5*ID, true]
-#heuristic node_compiler(node(ID, Package), CompilerID) : compiler_weight(CompilerID, 0), compiler_id(CompilerID), attr("node", node(ID, Package)), ID > 0. [25-5*ID, true]
-
-% node(ID, _), split build dependencies
-#heuristic attr("version", node(ID, Package), Version) : pkg_fact(Package, version_declared(Version, 0)), attr("node", node(ID, Package)), multiple_unification_sets(Package), ID > 0. [25, true]
-#heuristic version_weight(node(ID, Package), 0) : pkg_fact(Package, version_declared(Version, 0)), attr("node", node(ID, Package)), multiple_unification_sets(Package), ID > 0. [25, true]
-#heuristic attr("variant_value", node(ID, Package), Variant, Value) : variant_default_value(Package, Variant, Value), attr("node", node(ID, Package)), multiple_unification_sets(Package), ID > 0. [25, true]
-#heuristic attr("node_target", node(ID, Package), Target) : pkg_fact(Package, target_weight(Target, 0)), attr("node", node(ID, Package)), multiple_unification_sets(Package), ID > 0. [25, true]
-#heuristic node_target_weight(node(ID, Package), 0) : attr("node", node(ID, Package)), multiple_unification_sets(Package), ID > 0. [25, true]
-#heuristic node_compiler(node(ID, Package), CompilerID) : compiler_weight(CompilerID, 0), compiler_id(CompilerID), attr("node", node(ID, Package)), multiple_unification_sets(Package), ID > 0. [25, true]

lib/spack/spack/solver/libc_compatibility.lp

@@ -10,25 +10,31 @@
 %=============================================================================
 
 % A package cannot be reused if the libc is not compatible with it
-:- provider(node(X, LibcPackage), node(0, "libc")),
-   attr("version", node(X, LibcPackage), LibcVersion),
-   attr("hash", node(R, ReusedPackage), Hash),
-   % Libc packages can be reused without the "compatible_libc" attribute
-   ReusedPackage != LibcPackage,
-   not attr("compatible_libc", node(R, ReusedPackage), LibcPackage, LibcVersion).
-
-% Check whether the DAG has any built package
-has_built_packages() :- build(X), not external(X).
+error(100, "Cannot reuse {0} since we cannot determine libc compatibility", ReusedPackage)
+  :- provider(node(X, LibcPackage), node(0, "libc")),
+     attr("version", node(X, LibcPackage), LibcVersion),
+     attr("hash", node(R, ReusedPackage), Hash),
+     % Libc packages can be reused without the "compatible_libc" attribute
+     ReusedPackage != LibcPackage,
+     not attr("compatible_libc", node(R, ReusedPackage), LibcPackage, LibcVersion).
 
 % A libc is needed in the DAG
 :- has_built_packages(), not provider(_, node(0, "libc")).
 
-% The libc must be chosen among available ones
+% Non-libc reused specs must be host libc compatible. In case we build packages, we get a
+% host compatible libc provider from other rules. If nothing is built, there is no libc provider,
+% since it's pruned from reusable specs, meaning we have to explicitly impose reused specs are host
+% compatible.
+:- attr("hash", node(R, ReusedPackage), Hash),
+   not provider(node(R, ReusedPackage), node(0, "libc")),
+   not attr("compatible_libc", node(R, ReusedPackage), _, _).
+
+% The libc provider must be one that a compiler can target
 :- has_built_packages(),
    provider(node(X, LibcPackage), node(0, "libc")),
    attr("node", node(X, LibcPackage)),
    attr("version", node(X, LibcPackage), LibcVersion),
-   not allowed_libc(LibcPackage, LibcVersion).
+   not host_libc(LibcPackage, LibcVersion).
 
 % A built node must depend on libc
 :- build(PackageNode),

lib/spack/spack/spec.py

@@ -1287,6 +1287,102 @@ def copy(self, *args, **kwargs):
         return self.wrapped_obj.copy(*args, **kwargs)
 
 
+def tree(
+    specs: List["spack.spec.Spec"],
+    *,
+    color: Optional[bool] = None,
+    depth: bool = False,
+    hashes: bool = False,
+    hashlen: Optional[int] = None,
+    cover: str = "nodes",
+    indent: int = 0,
+    format: str = DEFAULT_FORMAT,
+    deptypes: Union[Tuple[str, ...], str] = "all",
+    show_types: bool = False,
+    depth_first: bool = False,
+    recurse_dependencies: bool = True,
+    status_fn: Optional[Callable[["Spec"], InstallStatus]] = None,
+    prefix: Optional[Callable[["Spec"], str]] = None,
+    key=id,
+) -> str:
+    """Prints out specs and their dependencies, tree-formatted with indentation.
+
+    Status function may either output a boolean or an InstallStatus
+
+    Args:
+        color: if True, always colorize the tree. If False, don't colorize the tree. If None,
+            use the default from llnl.tty.color
+        depth: print the depth from the root
+        hashes: if True, print the hash of each node
+        hashlen: length of the hash to be printed
+        cover: either "nodes" or "edges"
+        indent: extra indentation for the tree being printed
+        format: format to be used to print each node
+        deptypes: dependency types to be represented in the tree
+        show_types: if True, show the (merged) dependency type of a node
+        depth_first: if True, traverse the DAG depth first when representing it as a tree
+        recurse_dependencies: if True, recurse on dependencies
+        status_fn: optional callable that takes a node as an argument and return its
+            installation status
+        prefix: optional callable that takes a node as an argument and return its
+            installation prefix
+    """
+    out = ""
+
+    if color is None:
+        color = clr.get_color_when()
+
+    for d, dep_spec in traverse.traverse_tree(
+        sorted(specs), cover=cover, deptype=deptypes, depth_first=depth_first, key=key
+    ):
+        node = dep_spec.spec
+
+        if prefix is not None:
+            out += prefix(node)
+        out += " " * indent
+
+        if depth:
+            out += "%-4d" % d
+
+        if status_fn:
+            status = status_fn(node)
+            if status in list(InstallStatus):
+                out += clr.colorize(status.value, color=color)
+            elif status:
+                out += clr.colorize("@g{[+]}  ", color=color)
+            else:
+                out += clr.colorize("@r{[-]}  ", color=color)
+
+        if hashes:
+            out += clr.colorize("@K{%s}  ", color=color) % node.dag_hash(hashlen)
+
+        if show_types:
+            if cover == "nodes":
+                # when only covering nodes, we merge dependency types
+                # from all dependents before showing them.
+                depflag = 0
+                for ds in node.edges_from_dependents():
+                    depflag |= ds.depflag
+            else:
+                # when covering edges or paths, we show dependency
+                # types only for the edge through which we visited
+                depflag = dep_spec.depflag
+
+            type_chars = dt.flag_to_chars(depflag)
+            out += "[%s]  " % type_chars
+
+        out += "    " * d
+        if d > 0:
+            out += "^"
+        out += node.format(format, color=color) + "\n"
+
+        # Check if we wanted just the first line
+        if not recurse_dependencies:
+            break
+
+    return out
+
+
 @lang.lazy_lexicographic_ordering(set_hash=False)
 class Spec:
     #: Cache for spec's prefix, computed lazily in the corresponding property
@@ -2816,9 +2912,7 @@ def _old_concretize(self, tests=False, deprecation_warning=True):
 
         # Check if we can produce an optimized binary (will throw if
         # there are declared inconsistencies)
-        # No need on platform=cray because of the targeting modules
-        if not self.satisfies("platform=cray"):
-            self.architecture.target.optimization_flags(self.compiler)
+        self.architecture.target.optimization_flags(self.compiler)
 
     def _patches_assigned(self):
         """Whether patches have been assigned to this spec by the concretizer."""
@@ -4606,13 +4700,14 @@ def tree(
         recurse_dependencies: bool = True,
         status_fn: Optional[Callable[["Spec"], InstallStatus]] = None,
         prefix: Optional[Callable[["Spec"], str]] = None,
+        key=id,
     ) -> str:
-        """Prints out this spec and its dependencies, tree-formatted
-        with indentation.
+        """Prints out this spec and its dependencies, tree-formatted with indentation.
 
-        Status function may either output a boolean or an InstallStatus
+        See multi-spec ``spack.spec.tree()`` function for details.
 
         Args:
+            specs: List of specs to format.
             color: if True, always colorize the tree. If False, don't colorize the tree. If None,
                 use the default from llnl.tty.color
             depth: print the depth from the root
@@ -4630,60 +4725,23 @@ def tree(
             prefix: optional callable that takes a node as an argument and return its
                 installation prefix
         """
-        out = ""
-
-        if color is None:
-            color = clr.get_color_when()
-
-        for d, dep_spec in traverse.traverse_tree(
-            [self], cover=cover, deptype=deptypes, depth_first=depth_first
-        ):
-            node = dep_spec.spec
-
-            if prefix is not None:
-                out += prefix(node)
-            out += " " * indent
-
-            if depth:
-                out += "%-4d" % d
-
-            if status_fn:
-                status = status_fn(node)
-                if status in list(InstallStatus):
-                    out += clr.colorize(status.value, color=color)
-                elif status:
-                    out += clr.colorize("@g{[+]}  ", color=color)
-                else:
-                    out += clr.colorize("@r{[-]}  ", color=color)
-
-            if hashes:
-                out += clr.colorize("@K{%s}  ", color=color) % node.dag_hash(hashlen)
-
-            if show_types:
-                if cover == "nodes":
-                    # when only covering nodes, we merge dependency types
-                    # from all dependents before showing them.
-                    depflag = 0
-                    for ds in node.edges_from_dependents():
-                        depflag |= ds.depflag
-                else:
-                    # when covering edges or paths, we show dependency
-                    # types only for the edge through which we visited
-                    depflag = dep_spec.depflag
-
-                type_chars = dt.flag_to_chars(depflag)
-                out += "[%s]  " % type_chars
-
-            out += "    " * d
-            if d > 0:
-                out += "^"
-            out += node.format(format, color=color) + "\n"
-
-            # Check if we wanted just the first line
-            if not recurse_dependencies:
-                break
-
-        return out
+        return tree(
+            [self],
+            color=color,
+            depth=depth,
+            hashes=hashes,
+            hashlen=hashlen,
+            cover=cover,
+            indent=indent,
+            format=format,
+            deptypes=deptypes,
+            show_types=show_types,
+            depth_first=depth_first,
+            recurse_dependencies=recurse_dependencies,
+            status_fn=status_fn,
+            prefix=prefix,
+            key=key,
+        )
 
     def __repr__(self):
         return str(self)

lib/spack/spack/spec_list.py

@@ -212,10 +212,7 @@ def _expand_matrix_constraints(matrix_config):
     results = []
     for combo in itertools.product(*expanded_rows):
         # Construct a combined spec to test against excludes
-        flat_combo = [constraint for constraint_list in combo for constraint in constraint_list]
-
-        # Resolve abstract hashes so we can exclude by their concrete properties
-        flat_combo = [Spec(x).lookup_hash() for x in flat_combo]
+        flat_combo = [Spec(constraint) for constraints in combo for constraint in constraints]
 
         test_spec = flat_combo[0].copy()
         for constraint in flat_combo[1:]:
@@ -231,7 +228,9 @@ def _expand_matrix_constraints(matrix_config):
             spack.variant.substitute_abstract_variants(test_spec)
         except spack.variant.UnknownVariantError:
             pass
-        if any(test_spec.satisfies(x) for x in excludes):
+
+        # Resolve abstract hashes for exclusion criteria
+        if any(test_spec.lookup_hash().satisfies(x) for x in excludes):
             continue
 
         if sigil:

lib/spack/spack/stage.py

@@ -346,8 +346,6 @@ class Stage(LockableStagingDir):
     similar, and are intended to persist for only one run of spack.
     """
 
-    #: Most staging is managed by Spack. DIYStage is one exception.
-    needs_fetching = True
     requires_patch_success = True
 
     def __init__(
@@ -772,8 +770,6 @@ def __init__(self):
                 "cache_mirror",
                 "steal_source",
                 "disable_mirrors",
-                "needs_fetching",
-                "requires_patch_success",
             ]
         )
 
@@ -812,6 +808,10 @@ def path(self):
     def archive_file(self):
         return self[0].archive_file
 
+    @property
+    def requires_patch_success(self):
+        return self[0].requires_patch_success
+
     @property
     def keep(self):
         return self[0].keep
@@ -822,64 +822,7 @@ def keep(self, value):
             item.keep = value
 
 
-class DIYStage:
-    """
-    Simple class that allows any directory to be a spack stage.  Consequently,
-    it does not expect or require that the source path adhere to the standard
-    directory naming convention.
-    """
-
-    needs_fetching = False
-    requires_patch_success = False
-
-    def __init__(self, path):
-        if path is None:
-            raise ValueError("Cannot construct DIYStage without a path.")
-        elif not os.path.isdir(path):
-            raise StagePathError("The stage path directory does not exist:", path)
-
-        self.archive_file = None
-        self.path = path
-        self.source_path = path
-        self.created = True
-
-    # DIY stages do nothing as context managers.
-    def __enter__(self):
-        pass
-
-    def __exit__(self, exc_type, exc_val, exc_tb):
-        pass
-
-    def fetch(self, *args, **kwargs):
-        tty.debug("No need to fetch for DIY.")
-
-    def check(self):
-        tty.debug("No checksum needed for DIY.")
-
-    def expand_archive(self):
-        tty.debug("Using source directory: {0}".format(self.source_path))
-
-    @property
-    def expanded(self):
-        """Returns True since the source_path must exist."""
-        return True
-
-    def restage(self):
-        raise RestageError("Cannot restage a DIY stage.")
-
-    def create(self):
-        self.created = True
-
-    def destroy(self):
-        # No need to destroy DIY stage.
-        pass
-
-    def cache_local(self):
-        tty.debug("Sources for DIY stages are not cached")
-
-
 class DevelopStage(LockableStagingDir):
-    needs_fetching = False
     requires_patch_success = False
 
     def __init__(self, name, dev_path, reference_link):