Set version to v0.22.1

Fix message formatting of the "virtual dependency cannot have variants" error.

.github/workflows/audit.yaml

@@ -17,33 +17,51 @@ concurrency:
 jobs:
   # Run audits on all the packages in the built-in repository
   package-audits:
-    runs-on: ${{ matrix.operating_system }}
+    runs-on: ${{ matrix.system.os }}
     strategy:
       matrix:
-        operating_system: ["ubuntu-latest", "macos-latest"]
+        system:
+        - { os: windows-latest, shell: 'powershell Invoke-Expression -Command "./share/spack/qa/windows_test_setup.ps1"; {0}' }
+        - { os: ubuntu-latest, shell: bash }
+        - { os: macos-latest, shell: bash }
+    defaults:
+      run:
+        shell: ${{ matrix.system.shell }}
     steps:
-    - uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
+    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
       with:
         python-version: ${{inputs.python_version}}
     - name: Install Python packages
       run: |
         pip install --upgrade pip setuptools pytest coverage[toml]
+    - name: Setup for Windows run
+      if: runner.os == 'Windows'
+      run: |
+        python -m pip install --upgrade pywin32
     - name: Package audits (with coverage)
-      if: ${{ inputs.with_coverage == 'true' }}
+      if: ${{ inputs.with_coverage == 'true' && runner.os != 'Windows' }}
       run: |
           . share/spack/setup-env.sh
           coverage run $(which spack) audit packages
-          coverage run $(which spack) -d audit externals        
+          coverage run $(which spack) -d audit externals
           coverage combine
           coverage xml
     - name: Package audits (without coverage)
-      if: ${{ inputs.with_coverage == 'false' }}
+      if: ${{ inputs.with_coverage == 'false' && runner.os != 'Windows' }}
       run: |
-          . share/spack/setup-env.sh
-          $(which spack) audit packages
-          $(which spack) audit externals
-    - uses: codecov/codecov-action@84508663e988701840491b86de86b666e8a86bed
+          . share/spack/setup-env.sh          
+          spack -d audit packages
+          spack -d audit externals
+    - name: Package audits (without coverage)
+      if: ${{ runner.os == 'Windows' }}
+      run: |
+          . share/spack/setup-env.sh          
+          spack -d audit packages
+          ./share/spack/qa/validate_last_exit.ps1
+          spack -d audit externals
+          ./share/spack/qa/validate_last_exit.ps1
+    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
       if: ${{ inputs.with_coverage == 'true' }}
       with:
         flags: unittests,audits

.github/workflows/bootstrap-test.sh

@@ -1,7 +1,8 @@
 #!/bin/bash
-set -ex
+set -e
 source share/spack/setup-env.sh
+$PYTHON bin/spack bootstrap disable github-actions-v0.4
 $PYTHON bin/spack bootstrap disable spack-install
-$PYTHON bin/spack -d solve zlib
+$PYTHON bin/spack $SPACK_FLAGS solve zlib
 tree $BOOTSTRAP/store
 exit 0

.github/workflows/bootstrap.yml

@@ -13,118 +13,22 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  fedora-clingo-sources:
+  distros-clingo-sources:
     runs-on: ubuntu-latest
-    container: "fedora:latest"
+    container: ${{ matrix.image }}
+    strategy:
+      matrix:
+        image: ["fedora:latest", "opensuse/leap:latest"]
     steps:
-      - name: Install dependencies
+      - name: Setup Fedora
+        if: ${{ matrix.image == 'fedora:latest' }}
         run: |
           dnf install -y \
-              bzip2 curl file gcc-c++ gcc gcc-gfortran git gnupg2 gzip \
+              bzip2 curl file gcc-c++ gcc gcc-gfortran git gzip \
               make patch unzip which xz python3 python3-devel tree \
               cmake bison bison-devel libstdc++-static
-      - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
-        with:
-          fetch-depth: 0
-      - name: Setup non-root user
-        run: |
-          # See [1] below
-          git config --global --add safe.directory /__w/spack/spack
-          useradd spack-test && mkdir -p ~spack-test
-          chown -R spack-test . ~spack-test
-      - name: Setup repo
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          git --version
-          . .github/workflows/setup_git.sh
-      - name: Bootstrap clingo
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          source share/spack/setup-env.sh
-          spack bootstrap disable github-actions-v0.5
-          spack bootstrap disable github-actions-v0.4
-          spack external find cmake bison
-          spack -d solve zlib
-          tree ~/.spack/bootstrap/store/
-
-  ubuntu-clingo-sources:
-    runs-on: ubuntu-latest
-    container: "ubuntu:latest"
-    steps:
-      - name: Install dependencies
-        env:
-          DEBIAN_FRONTEND: noninteractive
-        run: |
-          apt-get update -y && apt-get upgrade -y
-          apt-get install -y \
-              bzip2 curl file g++ gcc gfortran git gnupg2 gzip \
-              make patch unzip xz-utils python3 python3-dev tree \
-              cmake bison
-      - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
-        with:
-          fetch-depth: 0
-      - name: Setup non-root user
-        run: |
-          # See [1] below
-          git config --global --add safe.directory /__w/spack/spack
-          useradd spack-test && mkdir -p ~spack-test
-          chown -R spack-test . ~spack-test
-      - name: Setup repo
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          git --version
-          . .github/workflows/setup_git.sh
-      - name: Bootstrap clingo
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          source share/spack/setup-env.sh
-          spack bootstrap disable github-actions-v0.5
-          spack bootstrap disable github-actions-v0.4
-          spack external find cmake bison
-          spack -d solve zlib
-          tree ~/.spack/bootstrap/store/
-
-  ubuntu-clingo-binaries-and-patchelf:
-    runs-on: ubuntu-latest
-    container: "ubuntu:latest"
-    steps:
-      - name: Install dependencies
-        env:
-          DEBIAN_FRONTEND: noninteractive
-        run: |
-          apt-get update -y && apt-get upgrade -y
-          apt-get install -y \
-              bzip2 curl file g++ gcc gfortran git gnupg2 gzip \
-              make patch unzip xz-utils python3 python3-dev tree
-      - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
-        with:
-          fetch-depth: 0
-      - name: Setup non-root user
-        run: |
-          # See [1] below
-          git config --global --add safe.directory /__w/spack/spack
-          useradd spack-test && mkdir -p ~spack-test
-          chown -R spack-test . ~spack-test
-      - name: Setup repo
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          git --version
-          . .github/workflows/setup_git.sh
-      - name: Bootstrap clingo
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          source share/spack/setup-env.sh
-          spack -d solve zlib
-          tree ~/.spack/bootstrap/store/
-
-  opensuse-clingo-sources:
-    runs-on: ubuntu-latest
-    container: "opensuse/leap:latest"
-    steps:
-      - name: Install dependencies
+      - name: Setup OpenSUSE
+        if: ${{ matrix.image == 'opensuse/leap:latest' }}
         run: |
           # Harden CI by applying the workaround described here: https://www.suse.com/support/kb/doc/?id=000019505
           zypper update -y || zypper update -y
@@ -133,15 +37,9 @@ jobs:
               make patch unzip which xz python3 python3-devel tree \
               cmake bison
       - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
+        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
         with:
           fetch-depth: 0
-      - name: Setup repo
-        run: |
-          # See [1] below
-          git config --global --add safe.directory /__w/spack/spack
-          git --version
-          . .github/workflows/setup_git.sh
       - name: Bootstrap clingo
         run: |
           source share/spack/setup-env.sh
@@ -151,77 +49,102 @@ jobs:
           spack -d solve zlib
           tree ~/.spack/bootstrap/store/
 
-  macos-clingo-sources:
-    runs-on: macos-latest
+  clingo-sources:
+    runs-on: ${{ matrix.runner }}
+    strategy:
+      matrix:
+        runner: ['macos-13', 'macos-14', "ubuntu-latest"]
     steps:
-      - name: Install dependencies
+      - name: Setup macOS
+        if: ${{ matrix.runner != 'ubuntu-latest' }}
         run: |
-          brew install cmake bison@2.7 tree
+          brew install cmake bison tree
       - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
+        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+        with:
+          fetch-depth: 0
       - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
         with:
           python-version: "3.12"
       - name: Bootstrap clingo
         run: |
           source share/spack/setup-env.sh
-          export PATH=/usr/local/opt/bison@2.7/bin:$PATH
           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/
 
-  macos-clingo-binaries:
-    runs-on: ${{ matrix.macos-version }}
+  gnupg-sources:
+    runs-on: ${{ matrix.runner }}
     strategy:
       matrix:
-        macos-version: ['macos-11', 'macos-12']
+        runner: [ 'macos-13', 'macos-14', "ubuntu-latest" ]
     steps:
-      - name: Install dependencies
+      - name: Setup macOS
+        if: ${{ matrix.runner != 'ubuntu-latest' }}
         run: |
           brew install tree
-      - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
-      - name: Bootstrap clingo
+          # Remove GnuPG since we want to bootstrap it
+          sudo rm -rf /usr/local/bin/gpg
+      - name: Setup Ubuntu
+        if: ${{ matrix.runner == 'ubuntu-latest' }}
         run: |
-          set -ex
-          for ver in '3.7' '3.8' '3.9' '3.10' '3.11' ; do
-            not_found=1
-            ver_dir="$(find $RUNNER_TOOL_CACHE/Python -wholename "*/${ver}.*/*/bin" | grep . || true)"
-            echo "Testing $ver_dir"
-            if [[ -d "$ver_dir" ]] ; then
-              if $ver_dir/python --version ; then
-                export PYTHON="$ver_dir/python"
-                not_found=0
-                old_path="$PATH"
-                export PATH="$ver_dir:$PATH"
-                ./bin/spack-tmpconfig -b ./.github/workflows/bootstrap-test.sh
-                export PATH="$old_path"
-              fi
-            fi
-            # NOTE: test all pythons that exist, not all do on 12
-          done
-
-  ubuntu-clingo-binaries:
-    runs-on: ubuntu-20.04
-    steps:
+          sudo rm -rf $(which gpg) $(which gpg2) $(which patchelf)
       - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
+        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
         with:
           fetch-depth: 0
-      - name: Setup repo
+      - name: Bootstrap GnuPG
         run: |
-          git --version
-          . .github/workflows/setup_git.sh
+          source share/spack/setup-env.sh
+          spack solve zlib
+          spack bootstrap disable github-actions-v0.5
+          spack bootstrap disable github-actions-v0.4
+          spack -d gpg list
+          tree ~/.spack/bootstrap/store/
+
+  from-binaries:
+    runs-on: ${{ matrix.runner }}
+    strategy:
+      matrix:
+        runner: ['macos-13', 'macos-14', "ubuntu-latest"]
+    steps:
+      - 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
+      - name: Setup Ubuntu
+        if: ${{ matrix.runner == 'ubuntu-latest' }}
+        run: |
+          sudo rm -rf $(which gpg) $(which gpg2) $(which patchelf)
+      - name: Checkout
+        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
+        with:
+          python-version: |
+            3.8
+            3.9
+            3.10
+            3.11
+            3.12
+      - name: Set bootstrap sources
+        run: |
+          source share/spack/setup-env.sh
+          spack bootstrap disable github-actions-v0.4
+          spack bootstrap disable spack-install
       - name: Bootstrap clingo
         run: |
-          set -ex
-          for ver in '3.7' '3.8' '3.9' '3.10' '3.11' ; do
+          set -e
+          for ver in '3.8' '3.9' '3.10' '3.11' '3.12' ; do
             not_found=1
             ver_dir="$(find $RUNNER_TOOL_CACHE/Python -wholename "*/${ver}.*/*/bin" | grep . || true)"
-            echo "Testing $ver_dir"
             if [[ -d "$ver_dir" ]] ; then
+              echo "Testing $ver_dir"
               if $ver_dir/python --version ; then
                 export PYTHON="$ver_dir/python"
                 not_found=0
@@ -236,122 +159,9 @@ jobs:
               exit 1
             fi
           done
-
-  ubuntu-gnupg-binaries:
-    runs-on: ubuntu-latest
-    container: "ubuntu:latest"
-    steps:
-      - name: Install dependencies
-        env:
-          DEBIAN_FRONTEND: noninteractive
-        run: |
-          apt-get update -y && apt-get upgrade -y
-          apt-get install -y \
-              bzip2 curl file g++ gcc patchelf gfortran git gzip \
-              make patch unzip xz-utils python3 python3-dev tree
-      - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
-        with:
-          fetch-depth: 0
-      - name: Setup non-root user
-        run: |
-          # See [1] below
-          git config --global --add safe.directory /__w/spack/spack
-          useradd spack-test && mkdir -p ~spack-test
-          chown -R spack-test . ~spack-test
-      - name: Setup repo
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          git --version
-          . .github/workflows/setup_git.sh
-      - name: Bootstrap GnuPG
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          source share/spack/setup-env.sh
-          spack bootstrap disable github-actions-v0.4
-          spack bootstrap disable spack-install
-          spack -d gpg list
-          tree ~/.spack/bootstrap/store/
-
-  ubuntu-gnupg-sources:
-    runs-on: ubuntu-latest
-    container: "ubuntu:latest"
-    steps:
-      - name: Install dependencies
-        env:
-          DEBIAN_FRONTEND: noninteractive
-        run: |
-          apt-get update -y && apt-get upgrade -y
-          apt-get install -y \
-              bzip2 curl file g++ gcc patchelf gfortran git gzip \
-              make patch unzip xz-utils python3 python3-dev tree \
-              gawk
-      - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
-        with:
-          fetch-depth: 0
-      - name: Setup non-root user
-        run: |
-          # See [1] below
-          git config --global --add safe.directory /__w/spack/spack
-          useradd spack-test && mkdir -p ~spack-test
-          chown -R spack-test . ~spack-test
-      - name: Setup repo
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          git --version
-          . .github/workflows/setup_git.sh
-      - name: Bootstrap GnuPG
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          source share/spack/setup-env.sh
-          spack solve zlib
-          spack bootstrap disable github-actions-v0.5
-          spack bootstrap disable github-actions-v0.4
-          spack -d gpg list
-          tree ~/.spack/bootstrap/store/
-
-  macos-gnupg-binaries:
-    runs-on: macos-latest
-    steps:
-      - name: Install dependencies
-        run: |
-          brew install tree
-          # Remove GnuPG since we want to bootstrap it
-          sudo rm -rf /usr/local/bin/gpg
-      - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
       - name: Bootstrap GnuPG
         run: |
           source share/spack/setup-env.sh
-          spack bootstrap disable github-actions-v0.4
-          spack bootstrap disable spack-install
           spack -d gpg list
           tree ~/.spack/bootstrap/store/
 
-  macos-gnupg-sources:
-    runs-on: macos-latest
-    steps:
-      - name: Install dependencies
-        run: |
-          brew install gawk tree
-          # Remove GnuPG since we want to bootstrap it
-          sudo rm -rf /usr/local/bin/gpg
-      - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
-      - name: Bootstrap GnuPG
-        run: |
-          source share/spack/setup-env.sh
-          spack solve zlib
-          spack bootstrap disable github-actions-v0.5
-          spack bootstrap disable github-actions-v0.4
-          spack -d gpg list
-          tree ~/.spack/bootstrap/store/
-
-
-# [1] Distros that have patched git to resolve CVE-2022-24765 (e.g. Ubuntu patching v2.25.1)
-#     introduce breaking behaviorso we have to set `safe.directory` in gitconfig ourselves.
-#     See:
-#     - https://github.blog/2022-04-12-git-security-vulnerability-announced/
-#     - https://github.com/actions/checkout/issues/760
-#     - http://changelogs.ubuntu.com/changelogs/pool/main/g/git/git_2.25.1-1ubuntu3.3/changelog

.github/workflows/build-containers.yml

@@ -45,19 +45,18 @@ jobs:
                      [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'],
+                     [ubuntu-noble, 'linux/amd64,linux/arm64,linux/ppc64le', 'ubuntu:24.04'],
                      [almalinux8, 'linux/amd64,linux/arm64,linux/ppc64le', 'almalinux:8'],
                      [almalinux9, 'linux/amd64,linux/arm64,linux/ppc64le', 'almalinux:9'],
                      [rockylinux8, 'linux/amd64,linux/arm64', 'rockylinux:8'],
                      [rockylinux9, 'linux/amd64,linux/arm64', 'rockylinux:9'],
-                     [fedora37, 'linux/amd64,linux/arm64,linux/ppc64le', 'fedora:37'],
-                     [fedora38, 'linux/amd64,linux/arm64,linux/ppc64le', 'fedora:38'],
                      [fedora39, 'linux/amd64,linux/arm64,linux/ppc64le', 'fedora:39'],
                      [fedora40, 'linux/amd64,linux/arm64,linux/ppc64le', 'fedora:40']]
     name: Build ${{ matrix.dockerfile[0] }}
     if: github.repository == 'spack/spack'
     steps:
       - name: Checkout
-        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
+        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
 
       - uses: docker/metadata-action@8e5442c4ef9f78752691e2d8f8d19755c6f78e81
         id: docker_meta
@@ -89,9 +88,9 @@ jobs:
           fi
 
       - name: Upload Dockerfile
-        uses: actions/upload-artifact@a8a3f3ad30e3422c9c7b888a15615d19a852ae32
+        uses: actions/upload-artifact@65462800fd760344b1a7b4382951275a0abb4808
         with:
-          name: dockerfiles
+          name: dockerfiles_${{ matrix.dockerfile[0] }}
           path: dockerfiles
 
       - name: Set up QEMU
@@ -122,3 +121,14 @@ jobs:
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.docker_meta.outputs.tags }}
           labels: ${{ steps.docker_meta.outputs.labels }}
+
+  merge-dockerfiles:
+    runs-on: ubuntu-latest
+    needs: deploy-images
+    steps:
+      - name: Merge Artifacts
+        uses: actions/upload-artifact/merge@65462800fd760344b1a7b4382951275a0abb4808
+        with:
+          name: dockerfiles
+          pattern: dockerfiles_*
+          delete-merged: true

.github/workflows/ci.yaml

@@ -36,7 +36,7 @@ jobs:
       core: ${{ steps.filter.outputs.core }}
       packages: ${{ steps.filter.outputs.packages }}
     steps:
-      - uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
+      - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
         if: ${{ github.event_name == 'push' }}
         with:
           fetch-depth: 0
@@ -77,13 +77,8 @@ 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@9bb56186c3b09b4f86b1c65136769dd318469633
+    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
       with:
         fetch-depth: 0
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d

.github/workflows/style/requirements.txt

@@ -1,4 +1,4 @@
-black==24.4.0
+black==24.4.2
 clingo==5.7.1
 flake8==7.0.0
 isort==5.13.2

.github/workflows/unit_tests.yaml

@@ -51,7 +51,7 @@ jobs:
           on_develop: false
 
     steps:
-    - uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
+    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
       with:
         fetch-depth: 0
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
@@ -91,7 +91,7 @@ jobs:
           UNIT_TEST_COVERAGE: ${{ matrix.python-version == '3.11' }}
       run: |
           share/spack/qa/run-unit-tests
-    - uses: codecov/codecov-action@84508663e988701840491b86de86b666e8a86bed
+    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
       with:
         flags: unittests,linux,${{ matrix.concretizer }}
         token: ${{ secrets.CODECOV_TOKEN }}
@@ -100,7 +100,7 @@ jobs:
   shell:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
+    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
       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@84508663e988701840491b86de86b666e8a86bed
+    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
       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@9bb56186c3b09b4f86b1c65136769dd318469633
+    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
     - 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@9bb56186c3b09b4f86b1c65136769dd318469633
+    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
       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@84508663e988701840491b86de86b666e8a86bed
+    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
       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@9bb56186c3b09b4f86b1c65136769dd318469633
+    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
       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@84508663e988701840491b86de86b666e8a86bed
+    - uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be
       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@125fc84a9a348dbcf27191600683ec096ec9021c
+      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@9bb56186c3b09b4f86b1c65136769dd318469633
+    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
     - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d
       with:
         python-version: '3.11'
@@ -35,7 +35,7 @@ jobs:
   style:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
+    - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
       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@9bb56186c3b09b4f86b1c65136769dd318469633
+      - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b
       - 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@9bb56186c3b09b4f86b1c65136769dd318469633
-      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@84508663e988701840491b86de86b666e8a86bed
-      with:
-        flags: unittests,windows
-        token: ${{ secrets.CODECOV_TOKEN }}
-        verbose: true
-  unit-tests-cmd:
-    runs-on: windows-latest
-    steps:
-    - uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
-      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@84508663e988701840491b86de86b666e8a86bed
-      with:
-        flags: unittests,windows
-        token: ${{ secrets.CODECOV_TOKEN }}
-        verbose: true
-  build-abseil:
-    runs-on: windows-latest
-    steps:
-    - uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633
-      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 +1,406 @@
+# v0.22.1 (2024-07-04)
+
+## Bugfixes
+- Fix reuse of externals on Linux (#44316)
+- Ensure parent gcc-runtime version >= child (#44834, #44870)
+- Ensure the latest gcc-runtime is rpath'ed when multiple exist among link deps (#44219)
+- Improve version detection of glibc (#44154)
+- Improve heuristics for solver (#44893, #44976, #45023)
+- Make strong preferences override reuse (#44373)
+- Reduce verbosity when C compiler is missing (#44182)
+- Make missing ccache executable an error when required (#44740)
+- Make every environment view containing `python` a `venv` (#44382)
+- Fix external detection for compilers with os but no target (#44156)
+- Fix version optimization for roots (#44272)
+- Handle common implementations of pagination of tags in OCI build caches (#43136)
+- Apply fetched patches to develop specs (#44950)
+- Avoid Windows wrappers for filesystem utilities on non-Windows (#44126)
+- Fix issue with long filenames in build caches on Windows (#43851)
+- Fix formatting issue in `spack audit` (#45045)
+- CI fixes (#44582, #43965, #43967, #44279, #44213)
+
+## Package updates
+- protobuf: fix 3.4:3.21 patch checksum (#44443)
+- protobuf: update hash for patch needed when="@3.4:3.21" (#44210)
+- git: bump v2.39 to 2.45; deprecate unsafe versions (#44248)
+- gcc: use -rpath {rpath_dir} not -rpath={rpath dir} (#44315)
+- Remove mesa18 and libosmesa (#44264)
+- Enforce consistency of `gl` providers (#44307)
+- Require libiconv for iconv (#44335, #45026).
+  Notice that glibc/musl also provide iconv, but are not guaranteed to be
+  complete. Set `packages:iconv:require:[glibc]` to restore the old behavior.
+- py-matplotlib: qualify when to do a post install (#44191)
+- rust: fix v1.78.0 instructions (#44127)
+- suite-sparse: improve setting of the `libs` property (#44214)
+- netlib-lapack: provide blas and lapack together (#44981)
+
+
+# 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.

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/linux/packages.yaml

@@ -0,0 +1,3 @@
+packages:
+  iconv:
+    require: [libiconv]

etc/spack/defaults/packages.yaml

@@ -18,6 +18,7 @@ packages:
     compiler: [gcc, clang, oneapi, xl, nag, fj, aocc]
     providers:
       awk: [gawk]
+      armci: [armcimpi]
       blas: [openblas, amdblis]
       D: [ldc]
       daal: [intel-oneapi-daal]
@@ -37,10 +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/_templates/layout.html

@@ -0,0 +1,12 @@
+{% extends "!layout.html" %}
+
+{%- block extrahead %} 
+  <!-- Google tag (gtag.js) -->
+  <script async src="https://www.googletagmanager.com/gtag/js?id=G-S0PQ7WV75K"></script>
+  <script>
+    window.dataLayer = window.dataLayer || [];
+    function gtag(){dataLayer.push(arguments);}
+    gtag('js', new Date());
+    gtag('config', 'G-S0PQ7WV75K');
+  </script>
+{% endblock %}

lib/spack/docs/basic_usage.rst

@@ -865,7 +865,7 @@ There are several different ways to use Spack packages once you have
 installed them. As you've seen, spack packages are installed into long
 paths with hashes, and you need a way to get them into your path. The
 easiest way is to use :ref:`spack load <cmd-spack-load>`, which is
-described in the next section.
+described in this section.
 
 Some more advanced ways to use Spack packages include:
 
@@ -959,7 +959,86 @@ use ``spack find --loaded``.
 You can also use ``spack load --list`` to get the same output, but it
 does not have the full set of query options that ``spack find`` offers.
 
-We'll learn more about Spack's spec syntax in the next section.
+We'll learn more about Spack's spec syntax in :ref:`a later section <sec-specs>`.
+
+
+.. _extensions:
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Python packages and virtual environments
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Spack can install a large number of Python packages. Their names are
+typically prefixed with ``py-``. Installing and using them is no
+different from any other package:
+
+.. code-block:: console
+
+   $ spack install py-numpy
+   $ spack load py-numpy
+   $ python3
+   >>> import numpy
+
+The ``spack load`` command sets the ``PATH`` variable so that the right Python
+executable is used, and makes sure that ``numpy`` and its dependencies can be
+located in the ``PYTHONPATH``.
+
+Spack is different from other Python package managers in that it installs
+every package into its *own* prefix. This is in contrast to ``pip``, which
+installs all packages into the same prefix, be it in a virtual environment
+or not.
+
+For many users, **virtual environments** are more convenient than repeated
+``spack load`` commands, particularly when working with multiple Python
+packages. Fortunately Spack supports environments itself, which together
+with a view are no different from Python virtual environments.
+
+The recommended way of working with Python extensions such as ``py-numpy``
+is through :ref:`Environments <environments>`. The following example creates
+a Spack environment with ``numpy`` in the current working directory. It also
+puts a filesystem view in ``./view``, which is a more traditional combined
+prefix for all packages in the environment.
+
+.. code-block:: console
+
+   $ spack env create --with-view view --dir .
+   $ spack -e . add py-numpy
+   $ spack -e . concretize
+   $ spack -e . install
+
+Now you can activate the environment and start using the packages:
+
+.. code-block:: console
+
+   $ spack env activate .
+   $ python3
+   >>> import numpy
+
+The environment view is also a virtual environment, which is useful if you are
+sharing the environment with others who are unfamiliar with Spack. They can
+either use the Python executable directly:
+
+.. code-block:: console
+
+   $ ./view/bin/python3
+   >>> import numpy
+
+or use the activation script:
+
+.. code-block:: console
+
+   $ source ./view/bin/activate
+   $ python3
+   >>> import numpy
+
+In general, there should not be much difference between ``spack env activate``
+and using the virtual environment. The main advantage of ``spack env activate``
+is that it knows about more packages than just Python packages, and it may set
+additional runtime variables that are not covered by the virtual environment
+activation script.
+
+See :ref:`environments` for a more in-depth description of Spack
+environments and customizations to views.
 
 
 .. _sec-specs:
@@ -1705,165 +1784,6 @@ check only local packages (as opposed to those used transparently from
 ``upstream`` spack instances) and the ``-j,--json`` option to output
 machine-readable json data for any errors.
 
-
-.. _extensions:
-
----------------------------
-Extensions & Python support
----------------------------
-
-Spack's installation model assumes that each package will live in its
-own install prefix.  However, certain packages are typically installed
-*within* the directory hierarchy of other packages.  For example,
-`Python <https://www.python.org>`_ packages are typically installed in the
-``$prefix/lib/python-2.7/site-packages`` directory.
-
-In Spack, installation prefixes are immutable, so this type of installation
-is not directly supported. However, it is possible to create views that
-allow you to merge install prefixes of multiple packages into a single new prefix.
-Views are a convenient way to get a more traditional filesystem structure.
-Using *extensions*, you can ensure that Python packages always share the
-same prefix in the view as Python itself. Suppose you have
-Python installed like so:
-
-.. code-block:: console
-
-   $ spack find python
-   ==> 1 installed packages.
-   -- linux-debian7-x86_64 / gcc@4.4.7 --------------------------------
-   python@2.7.8
-
-.. _cmd-spack-extensions:
-
-^^^^^^^^^^^^^^^^^^^^
-``spack extensions``
-^^^^^^^^^^^^^^^^^^^^
-
-You can find extensions for your Python installation like this:
-
-.. code-block:: console
-
-   $ spack extensions python
-   ==> python@2.7.8%gcc@4.4.7 arch=linux-debian7-x86_64-703c7a96
-   ==> 36 extensions:
-   geos          py-ipython     py-pexpect    py-pyside            py-sip
-   py-basemap    py-libxml2     py-pil        py-pytz              py-six
-   py-biopython  py-mako        py-pmw        py-rpy2              py-sympy
-   py-cython     py-matplotlib  py-pychecker  py-scientificpython  py-virtualenv
-   py-dateutil   py-mpi4py      py-pygments   py-scikit-learn
-   py-epydoc     py-mx          py-pylint     py-scipy
-   py-gnuplot    py-nose        py-pyparsing  py-setuptools
-   py-h5py       py-numpy       py-pyqt       py-shiboken
-
-   ==> 12 installed:
-   -- linux-debian7-x86_64 / gcc@4.4.7 --------------------------------
-   py-dateutil@2.4.0    py-nose@1.3.4       py-pyside@1.2.2
-   py-dateutil@2.4.0    py-numpy@1.9.1      py-pytz@2014.10
-   py-ipython@2.3.1     py-pygments@2.0.1   py-setuptools@11.3.1
-   py-matplotlib@1.4.2  py-pyparsing@2.0.3  py-six@1.9.0
-
-The extensions are a subset of what's returned by ``spack list``, and
-they are packages like any other.  They are installed into their own
-prefixes, and you can see this with ``spack find --paths``:
-
-.. code-block:: console
-
-   $ spack find --paths py-numpy
-   ==> 1 installed packages.
-   -- linux-debian7-x86_64 / gcc@4.4.7 --------------------------------
-       py-numpy@1.9.1  ~/spack/opt/linux-debian7-x86_64/gcc@4.4.7/py-numpy@1.9.1-66733244
-
-However, even though this package is installed, you cannot use it
-directly when you run ``python``:
-
-.. code-block:: console
-
-   $ spack load python
-   $ python
-   Python 2.7.8 (default, Feb 17 2015, 01:35:25)
-   [GCC 4.4.7 20120313 (Red Hat 4.4.7-11)] on linux2
-   Type "help", "copyright", "credits" or "license" for more information.
-   >>> import numpy
-   Traceback (most recent call last):
-     File "<stdin>", line 1, in <module>
-   ImportError: No module named numpy
-   >>>
-
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Using Extensions in Environments
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-The recommended way of working with extensions such as ``py-numpy``
-above is through :ref:`Environments <environments>`. For example,
-the following creates an environment in the current working directory
-with a filesystem view in the ``./view`` directory:
-
-.. code-block:: console
-
-   $ spack env create --with-view view --dir .
-   $ spack -e . add py-numpy
-   $ spack -e . concretize
-   $ spack -e . install
-
-We recommend environments for two reasons. Firstly, environments
-can be activated (requires :ref:`shell-support`):
-
-.. code-block:: console
-
-   $ spack env activate .
-
-which sets all the right environment variables such as ``PATH`` and
-``PYTHONPATH``. This ensures that
-
-.. code-block:: console
-
-   $ python
-   >>> import numpy
-
-works. Secondly, even without shell support, the view ensures
-that Python can locate its extensions:
-
-.. code-block:: console
-
-   $ ./view/bin/python
-   >>> import numpy
-
-See :ref:`environments` for a more in-depth description of Spack
-environments and customizations to views.
-
-^^^^^^^^^^^^^^^^^^^^
-Using ``spack load``
-^^^^^^^^^^^^^^^^^^^^
-
-A more traditional way of using Spack and extensions is ``spack load``
-(requires :ref:`shell-support`). This will add the extension to ``PYTHONPATH``
-in your current shell, and Python itself will be available in the ``PATH``:
-
-.. code-block:: console
-
-   $ spack load py-numpy
-   $ python
-   >>> import numpy
-
-The loaded packages can be checked using ``spack find --loaded``
-
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Loading Extensions via Modules
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Apart from ``spack env activate`` and ``spack load``, you can load numpy
-through your environment modules (using ``environment-modules`` or
-``lmod``). This will also add the extension to the ``PYTHONPATH`` in
-your current shell.
-
-.. code-block:: console
-
-   $ module load <name of numpy module>
-
-If you do not know the name of the specific numpy module you wish to
-load, you can use the ``spack module tcl|lmod loads`` command to get
-the name of the module from the Spack spec.
-
 -----------------------
 Filesystem requirements
 -----------------------

lib/spack/docs/build_settings.rst

@@ -21,23 +21,86 @@ is the following:
 Reuse already installed packages
 --------------------------------
 
-The ``reuse`` attribute controls whether Spack will prefer to use installed packages (``true``), or
-whether it will do a "fresh" installation and prefer the latest settings from
-``package.py`` files and ``packages.yaml`` (``false``).
-You can use:
+The ``reuse`` attribute controls how aggressively Spack reuses binary packages during concretization. The
+attribute can either be a single value, or an object for more complex configurations.
+
+In the former case ("single value") it allows Spack to:
+
+1. Reuse installed packages and buildcaches for all the specs to be concretized, when ``true``
+2. Reuse installed packages and buildcaches only for the dependencies of the root specs, when ``dependencies``
+3. Disregard reusing installed packages and buildcaches, when ``false``
+
+In case a finer control over which specs are reused is needed, then the value of this attribute can be
+an object, with the following keys:
+
+1. ``roots``: if ``true`` root specs are reused, if ``false`` only dependencies of root specs are reused
+2. ``from``: list of sources from which reused specs are taken
+
+Each source in ``from`` is itself an object:
+
+.. list-table:: Attributes for a source or reusable specs
+   :header-rows: 1
+
+   * - Attribute name
+     - Description
+   * - type (mandatory, string)
+     - Can be ``local``, ``buildcache``, or ``external``
+   * - include (optional, list of specs)
+     - If present, reusable specs must match at least one of the constraint in the list
+   * - exclude (optional, list of specs)
+     - If present, reusable specs must not match any of the constraint in the list.
+
+For instance, the following configuration:
+
+.. code-block:: yaml
+
+   concretizer:
+     reuse:
+       roots: true
+       from:
+       - type: local
+         include:
+         - "%gcc"
+         - "%clang"
+
+tells the concretizer to reuse all specs compiled with either ``gcc`` or ``clang``, that are installed
+in the local store. Any spec from remote buildcaches is disregarded.
+
+To reduce the boilerplate in configuration files, default values for the ``include`` and
+``exclude`` options can be pushed up one level:
+
+.. code-block:: yaml
+
+   concretizer:
+     reuse:
+       roots: true
+       include:
+       - "%gcc"
+       from:
+       - type: local
+       - type: buildcache
+       - type: local
+         include:
+         - "foo %oneapi"
+
+In the example above we reuse all specs compiled with ``gcc`` from the local store
+and remote buildcaches, and we also reuse ``foo %oneapi``. Note that the last source of
+specs override the default ``include`` attribute.
+
+For one-off concretizations, the are command line arguments for each of the simple "single value"
+configurations. This means a user can:
 
 .. code-block:: console
 
    % spack install --reuse <spec>
 
-to enable reuse for a single installation, and you can use:
+to enable reuse for a single installation, or:
 
 .. code-block:: console
 
    spack install --fresh <spec>
 
 to do a fresh install if ``reuse`` is enabled by default.
-``reuse: dependencies`` is the default.
 
 .. seealso::
 

lib/spack/docs/build_systems/pythonpackage.rst

@@ -718,23 +718,45 @@ command-line tool, or C/C++/Fortran program with optional Python
 modules? The former should be prepended with ``py-``, while the
 latter should not.
 
-""""""""""""""""""""""
-extends vs. depends_on
-""""""""""""""""""""""
+""""""""""""""""""""""""""""""
+``extends`` vs. ``depends_on``
+""""""""""""""""""""""""""""""
 
-This is very similar to the naming dilemma above, with a slight twist.
 As mentioned in the :ref:`Packaging Guide <packaging_extensions>`,
 ``extends`` and ``depends_on`` are very similar, but ``extends`` ensures
 that the extension and extendee share the same prefix in views.
 This allows the user to import a Python module without
 having to add that module to ``PYTHONPATH``.
 
-When deciding between ``extends`` and ``depends_on``, the best rule of
-thumb is to check the installation prefix. If Python libraries are
-installed to ``<prefix>/lib/pythonX.Y/site-packages``, then you
-should use ``extends``. If Python libraries are installed elsewhere
-or the only files that get installed reside in ``<prefix>/bin``, then
-don't use ``extends``.
+Additionally, ``extends("python")`` adds a dependency on the package
+``python-venv``. This improves isolation from the system, whether
+it's during the build or at runtime: user and system site packages
+cannot accidentally be used by any package that ``extends("python")``.
+
+As a rule of thumb: if a package does not install any Python modules
+of its own, and merely puts a Python script in the ``bin`` directory,
+then there is no need for ``extends``. If the package installs modules
+in the ``site-packages`` directory, it requires ``extends``.
+
+"""""""""""""""""""""""""""""""""""""
+Executing ``python`` during the build
+"""""""""""""""""""""""""""""""""""""
+
+Whenever you need to execute a Python command or pass the path of the
+Python interpreter to the build system, it is best to use the global
+variable ``python`` directly. For example:
+
+.. code-block:: python
+
+    @run_before("install")
+    def recythonize(self):
+        python("setup.py", "clean")  # use the `python` global
+
+As mentioned in the previous section, ``extends("python")`` adds an
+automatic dependency on ``python-venv``, which is a virtual environment
+that guarantees build isolation. The ``python`` global always refers to
+the correct Python interpreter, whether the package uses ``extends("python")``
+or ``depends_on("python")``.
 
 ^^^^^^^^^^^^^^^^^^^^^
 Alternatives to Spack

lib/spack/docs/config_yaml.rst

@@ -150,7 +150,7 @@ this can expose you to attacks.  Use at your own risk.
 --------------------
 
 Path to custom certificats for SSL verification. The value can be a 
-filesytem path, or an environment variable that expands to a file path.
+filesytem path, or an environment variable that expands to an absolute file path.
 The default value is set to the environment variable ``SSL_CERT_FILE``
 to use the same syntax used by many other applications that automatically
 detect custom certificates.
@@ -160,6 +160,9 @@ in the subprocess calling ``curl``.
 If ``url_fetch_method:urllib`` then files and directories are supported i.e. 
 ``config:ssl_certs:$SSL_CERT_FILE`` or ``config:ssl_certs:$SSL_CERT_DIR``
 will work.
+In all cases the expanded path must be absolute for Spack to use the certificates.
+Certificates relative to an environment can be created by prepending the path variable
+with the Spack configuration variable``$env``.
 
 --------------------
 ``checksum``

lib/spack/docs/containers.rst

@@ -194,15 +194,15 @@ The OS that are currently supported are summarized in the table below:
    * - Operating System
      - Base Image
      - Spack Image
-   * - Ubuntu 18.04
-     - ``ubuntu:18.04``
-     - ``spack/ubuntu-bionic``
    * - Ubuntu 20.04
      - ``ubuntu:20.04``
      - ``spack/ubuntu-focal``
    * - Ubuntu 22.04
      - ``ubuntu:22.04``
      - ``spack/ubuntu-jammy``
+   * - Ubuntu 24.04
+     - ``ubuntu:24.04``
+     - ``spack/ubuntu-noble``
    * - CentOS 7
      - ``centos:7``
      - ``spack/centos7``
@@ -227,12 +227,6 @@ The OS that are currently supported are summarized in the table below:
    * - Rocky Linux 9
      - ``rockylinux:9``
      - ``spack/rockylinux9``
-   * - Fedora Linux 37
-     - ``fedora:37``
-     - ``spack/fedora37``
-   * - Fedora Linux 38
-     - ``fedora:38``
-     - ``spack/fedora38``
    * - Fedora Linux 39
      - ``fedora:39``
      - ``spack/fedora39``

lib/spack/docs/environments.rst

@@ -142,12 +142,8 @@ user's prompt to begin with the environment name in brackets.
    $ spack env activate -p myenv
    [myenv] $ ...
 
-The ``activate`` command can also be used to create a new environment, if it is
-not already defined, by adding the ``--create`` flag. Managed and anonymous
-environments, anonymous environments are explained in the next section,
-can both be created using the same flags that `spack env create` accepts.
-If an environment already exists then spack will simply activate it and ignore the
-create specific flags.
+The ``activate`` command can also be used to create a new environment if it does not already
+exist.
 
 .. code-block:: console
    
@@ -176,21 +172,36 @@ environment will remove the view from the user environment.
 Anonymous Environments
 ^^^^^^^^^^^^^^^^^^^^^^
 
-Any directory can be treated as an environment if it contains a file
-``spack.yaml``. To load an anonymous environment, use:
+Apart from managed environments, Spack also supports anonymous environments.
+
+Anonymous environments can be placed in any directory of choice.
+
+.. note::
+
+   When uninstalling packages, Spack asks the user to confirm the removal of packages
+   that are still used in a managed environment. This is not the case for anonymous
+   environments.
+
+To create an anonymous environment, use one of the following commands:
 
 .. code-block:: console
 
-   $ spack env activate -d /path/to/directory
+   $ spack env create --dir my_env
+   $ spack env create ./my_env
 
-Anonymous specs can be created in place using the command:
+As a shorthand, you can also create an anonymous environment upon activation if it does not
+already exist:
 
 .. code-block:: console
 
-   $ spack env create -d .
+   $ spack env activate --create ./my_env
+
+For convenience, Spack can also place an anonymous environment in a temporary directory for you:
+
+.. code-block:: console
+
+   $ spack env activate --temp
 
-In this case Spack simply creates a ``spack.yaml`` file in the requested
-directory.
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Environment Sensitive Commands
@@ -449,6 +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:
 
 ------------------------
@@ -800,6 +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
 ----------------
@@ -1033,7 +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
@@ -1126,7 +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
 
@@ -1148,7 +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

@@ -478,6 +478,13 @@ prefix, you can add them to the ``extra_attributes`` field. Similarly,
 all other fields from the compilers config can be added to the
 ``extra_attributes`` field for an external representing a compiler.
 
+Note that the format for the ``paths`` field in the
+``extra_attributes`` section is different than in the ``compilers``
+config. For compilers configured as external packages, the section is
+named ``compilers`` and the dictionary maps language names (``c``,
+``cxx``, ``fortran``) to paths, rather than using the names ``cc``,
+``fc``, and ``f77``.
+
 .. code-block:: yaml
 
    packages:
@@ -493,11 +500,10 @@ all other fields from the compilers config can be added to the
        - spec: llvm+clang@15.0.0 arch=linux-rhel8-skylake
          prefix: /usr
          extra_attributes:
-           paths:
-             cc: /usr/bin/clang-with-suffix
+           compilers:
+             c: /usr/bin/clang-with-suffix
              cxx: /usr/bin/clang++-with-extra-info
-             fc: /usr/bin/gfortran
-             f77: /usr/bin/gfortran
+             fortran: /usr/bin/gfortran
            extra_rpaths:
            - /usr/lib/llvm/
 
@@ -1572,6 +1578,8 @@ Microsoft Visual Studio
 """""""""""""""""""""""
 
 Microsoft Visual Studio provides the only Windows C/C++ compiler that is currently supported by Spack.
+Spack additionally requires that the Windows SDK (including WGL) to be installed as part of your
+visual studio installation as it is required to build many packages from source.
 
 We require several specific components to be included in the Visual Studio installation.
 One is the C/C++ toolset, which can be selected as "Desktop development with C++" or "C++ build tools,"
@@ -1579,6 +1587,7 @@ depending on installation type (Professional, Build Tools, etc.)  The other requ
 "C++ CMake tools for Windows," which can be selected from among the optional packages.
 This provides CMake and Ninja for use during Spack configuration.
 
+
 If you already have Visual Studio installed, you can make sure these components are installed by
 rerunning the installer.  Next to your installation, select "Modify" and look at the
 "Installation details" pane on the right.

lib/spack/docs/requirements.txt

@@ -6,8 +6,8 @@ python-levenshtein==0.25.1
 docutils==0.20.1
 pygments==2.17.2
 urllib3==2.2.1
-pytest==8.1.1
+pytest==8.2.0
 isort==5.13.2
-black==24.4.0
+black==24.4.2
 flake8==7.0.0
-mypy==1.9.0
+mypy==1.10.0

lib/spack/external/__init__.py

@@ -18,7 +18,7 @@
 
 * Homepage: https://pypi.python.org/pypi/archspec
 * Usage: Labeling, comparison and detection of microarchitectures
-* Version: 0.2.3 (commit 7b8fe60b69e2861e7dac104bc1c183decfcd3daf)
+* Version: 0.2.4 (commit 48b92512b9ce203ded0ebd1ac41b42593e931f7c)
 
 astunparse
 ----------------

lib/spack/external/archspec/__init__.py

@@ -1,3 +1,3 @@
 """Init file to avoid namespace packages"""
 
-__version__ = "0.2.3"
+__version__ = "0.2.4"

lib/spack/external/archspec/cpu/__init__.py

@@ -5,9 +5,10 @@
 """The "cpu" package permits to query and compare different
 CPU microarchitectures.
 """
-from .detect import host
+from .detect import brand_string, host
 from .microarchitecture import (
     TARGETS,
+    InvalidCompilerVersion,
     Microarchitecture,
     UnsupportedMicroarchitecture,
     generic_microarchitecture,
@@ -15,10 +16,12 @@
 )
 
 __all__ = [
+    "brand_string",
+    "host",
+    "TARGETS",
+    "InvalidCompilerVersion",
     "Microarchitecture",
     "UnsupportedMicroarchitecture",
-    "TARGETS",
     "generic_microarchitecture",
-    "host",
     "version_components",
 ]

lib/spack/external/archspec/cpu/detect.py

@@ -155,6 +155,31 @@ def _is_bit_set(self, register: int, bit: int) -> bool:
         mask = 1 << bit
         return register & mask > 0
 
+    def brand_string(self) -> Optional[str]:
+        """Returns the brand string, if available."""
+        if self.highest_extension_support < 0x80000004:
+            return None
+
+        r1 = self.cpuid.registers_for(eax=0x80000002, ecx=0)
+        r2 = self.cpuid.registers_for(eax=0x80000003, ecx=0)
+        r3 = self.cpuid.registers_for(eax=0x80000004, ecx=0)
+        result = struct.pack(
+            "IIIIIIIIIIII",
+            r1.eax,
+            r1.ebx,
+            r1.ecx,
+            r1.edx,
+            r2.eax,
+            r2.ebx,
+            r2.ecx,
+            r2.edx,
+            r3.eax,
+            r3.ebx,
+            r3.ecx,
+            r3.edx,
+        ).decode("utf-8")
+        return result.strip("\x00")
+
 
 @detection(operating_system="Windows")
 def cpuid_info():
@@ -174,8 +199,8 @@ def _check_output(args, env):
 
 
 WINDOWS_MAPPING = {
-    "AMD64": "x86_64",
-    "ARM64": "aarch64",
+    "AMD64": X86_64,
+    "ARM64": AARCH64,
 }
 
 
@@ -409,3 +434,16 @@ def compatibility_check_for_riscv64(info, target):
     return (target == arch_root or arch_root in target.ancestors) and (
         target.name == info.name or target.vendor == "generic"
     )
+
+
+def brand_string() -> Optional[str]:
+    """Returns the brand string of the host, if detected, or None."""
+    if platform.system() == "Darwin":
+        return _check_output(
+            ["sysctl", "-n", "machdep.cpu.brand_string"], env=_ensure_bin_usrbin_in_path()
+        ).strip()
+
+    if host().family == X86_64:
+        return CpuidInfoCollector().brand_string()
+
+    return None

lib/spack/external/archspec/cpu/microarchitecture.py

@@ -208,6 +208,8 @@ def optimization_flags(self, compiler, version):
         """Returns a string containing the optimization flags that needs
         to be used to produce code optimized for this micro-architecture.
 
+        The version is expected to be a string of dot separated digits.
+
         If there is no information on the compiler passed as argument the
         function returns an empty string. If it is known that the compiler
         version we want to use does not support this architecture the function
@@ -216,6 +218,11 @@ def optimization_flags(self, compiler, version):
         Args:
             compiler (str): name of the compiler to be used
             version (str): version of the compiler to be used
+
+        Raises:
+            UnsupportedMicroarchitecture: if the requested compiler does not support
+                this micro-architecture.
+            ValueError: if the version doesn't match the expected format
         """
         # If we don't have information on compiler at all return an empty string
         if compiler not in self.family.compilers:
@@ -232,6 +239,14 @@ def optimization_flags(self, compiler, version):
             msg = msg.format(compiler, best_target, best_target.family)
             raise UnsupportedMicroarchitecture(msg)
 
+        # Check that the version matches the expected format
+        if not re.match(r"^(?:\d+\.)*\d+$", version):
+            msg = (
+                "invalid format for the compiler version argument. "
+                "Only dot separated digits are allowed."
+            )
+            raise InvalidCompilerVersion(msg)
+
         # If we have information on this compiler we need to check the
         # version being used
         compiler_info = self.compilers[compiler]
@@ -292,7 +307,7 @@ def generic_microarchitecture(name):
     Args:
         name (str): name of the micro-architecture
     """
-    return Microarchitecture(name, parents=[], vendor="generic", features=[], compilers={})
+    return Microarchitecture(name, parents=[], vendor="generic", features=set(), compilers={})
 
 
 def version_components(version):
@@ -367,7 +382,15 @@ def fill_target_from_dict(name, data, targets):
 TARGETS = LazyDictionary(_known_microarchitectures)
 
 
-class UnsupportedMicroarchitecture(ValueError):
+class ArchspecError(Exception):
+    """Base class for errors within archspec"""
+
+
+class UnsupportedMicroarchitecture(ArchspecError, ValueError):
     """Raised if a compiler version does not support optimization for a given
     micro-architecture.
     """
+
+
+class InvalidCompilerVersion(ArchspecError, ValueError):
+    """Raised when an invalid format is used for compiler versions in archspec."""

lib/spack/external/archspec/json/cpu/microarchitectures.json

@@ -2937,8 +2937,6 @@
           "ilrcpc",
           "flagm",
           "ssbs",
-          "paca",
-          "pacg",
           "dcpodp",
           "svei8mm",
           "svebf16",
@@ -3066,8 +3064,6 @@
 	  "flagm",
 	  "ssbs",
 	  "sb",
-	  "paca",
-	  "pacg",
 	  "dcpodp",
 	  "sve2",
 	  "sveaes",
@@ -3081,8 +3077,7 @@
 	  "svebf16",
 	  "i8mm",
 	  "bf16",
-	  "dgh",
-	  "bti"
+	  "dgh"
       ],
       "compilers" : {
           "gcc": [

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)
 
@@ -822,7 +843,7 @@ 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):
@@ -2429,9 +2450,10 @@ 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 +2531,14 @@ 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

@@ -11,7 +11,7 @@
 
 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
@@ -247,9 +247,9 @@ 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 +269,14 @@ def _windows_create_hard_link(path: str, link: str):
         CreateHardLink(link, path)
 
 
-def readlink(path: str):
+def 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:

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

@@ -59,6 +59,7 @@
 
 To output an @, use '@@'.  To output a } inside braces, use '}}'.
 """
+import os
 import re
 import sys
 from contextlib import contextmanager
@@ -101,9 +102,29 @@ def __init__(self, message):
 # Mapping from color arguments to values for tty.set_color
 color_when_values = {"always": True, "auto": None, "never": False}
 
-# Force color; None: Only color if stdout is a tty
-# True: Always colorize output, False: Never colorize output
-_force_color = None
+
+def _color_when_value(when):
+    """Raise a ValueError for an invalid color setting.
+
+    Valid values are 'always', 'never', and 'auto', or equivalently,
+    True, False, and None.
+    """
+    if when in color_when_values:
+        return color_when_values[when]
+    elif when not in color_when_values.values():
+        raise ValueError("Invalid color setting: %s" % when)
+    return when
+
+
+def _color_from_environ() -> Optional[bool]:
+    try:
+        return _color_when_value(os.environ.get("SPACK_COLOR", "auto"))
+    except ValueError:
+        return None
+
+
+#: When `None` colorize when stdout is tty, when `True` or `False` always or never colorize resp.
+_force_color = _color_from_environ()
 
 
 def try_enable_terminal_color_on_windows():
@@ -164,19 +185,6 @@ def _err_check(result, func, args):
             debug("Unable to support color on Windows terminal")
 
 
-def _color_when_value(when):
-    """Raise a ValueError for an invalid color setting.
-
-    Valid values are 'always', 'never', and 'auto', or equivalently,
-    True, False, and None.
-    """
-    if when in color_when_values:
-        return color_when_values[when]
-    elif when not in color_when_values.values():
-        raise ValueError("Invalid color setting: %s" % when)
-    return when
-
-
 def get_color_when():
     """Return whether commands should print color or not."""
     if _force_color is not None:

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__ = "0.22.1"
 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")
 
@@ -779,7 +779,7 @@ 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)
 
@@ -1046,7 +1046,7 @@ def _extracts_errors(triggers, summary):
     group="externals",
     tag="PKG-EXTERNALS",
     description="Sanity checks for external software detection",
-    kwargs=("pkgs",),
+    kwargs=("pkgs", "debug_log"),
 )
 
 
@@ -1069,7 +1069,7 @@ def packages_with_detection_tests():
 
 
 @external_detection
-def _test_detection_by_executable(pkgs, error_cls):
+def _test_detection_by_executable(pkgs, debug_log, error_cls):
     """Test drive external detection for packages"""
     import spack.detection
 
@@ -1095,6 +1095,7 @@ def _test_detection_by_executable(pkgs, error_cls):
         for idx, test_runner in enumerate(
             spack.detection.detection_tests(pkg_name, spack.repo.PATH)
         ):
+            debug_log(f"[{__file__}]: running test {idx} for package {pkg_name}")
             specs = test_runner.execute()
             expected_specs = test_runner.expected_specs
 
@@ -1115,11 +1116,10 @@ def _test_detection_by_executable(pkgs, error_cls):
             for candidate in expected_specs:
                 try:
                     idx = specs.index(candidate)
+                    matched_detection.append((candidate, specs[idx]))
                 except (AttributeError, ValueError):
                     pass
 
-                matched_detection.append((candidate, specs[idx]))
-
             def _compare_extra_attribute(_expected, _detected, *, _spec):
                 result = []
                 # Check items are of the same type

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/__init__.py

@@ -5,7 +5,13 @@
 """Function and classes needed to bootstrap Spack itself."""
 
 from .config import ensure_bootstrap_configuration, is_bootstrapping, store_path
-from .core import all_core_root_specs, ensure_core_dependencies, ensure_patchelf_in_path_or_raise
+from .core import (
+    all_core_root_specs,
+    ensure_clingo_importable_or_raise,
+    ensure_core_dependencies,
+    ensure_gpg_in_path_or_raise,
+    ensure_patchelf_in_path_or_raise,
+)
 from .environment import BootstrapEnvironment, ensure_environment_dependencies
 from .status import status_message
 
@@ -13,6 +19,8 @@
     "is_bootstrapping",
     "ensure_bootstrap_configuration",
     "ensure_core_dependencies",
+    "ensure_gpg_in_path_or_raise",
+    "ensure_clingo_importable_or_raise",
     "ensure_patchelf_in_path_or_raise",
     "all_core_root_specs",
     "ensure_environment_dependencies",

lib/spack/spack/bootstrap/_common.py

@@ -54,10 +54,14 @@ def _try_import_from_store(
     installed_specs = spack.store.STORE.db.query(query_spec, installed=True)
 
     for candidate_spec in installed_specs:
-        pkg = candidate_spec["python"].package
+        # previously bootstrapped specs may not have a python-venv dependency.
+        if candidate_spec.dependencies("python-venv"):
+            python, *_ = candidate_spec.dependencies("python-venv")
+        else:
+            python, *_ = candidate_spec.dependencies("python")
         module_paths = [
-            os.path.join(candidate_spec.prefix, pkg.purelib),
-            os.path.join(candidate_spec.prefix, pkg.platlib),
+            os.path.join(candidate_spec.prefix, python.package.purelib),
+            os.path.join(candidate_spec.prefix, python.package.platlib),
         ]
         path_before = list(sys.path)
 

lib/spack/spack/bootstrap/core.py

@@ -270,10 +270,6 @@ def try_import(self, module: str, abstract_spec_str: str) -> bool:
         with spack_python_interpreter():
             # Add hint to use frontend operating system on Cray
             concrete_spec = spack.spec.Spec(abstract_spec_str + " ^" + spec_for_current_python())
-            # This is needed to help the old concretizer taking the `setuptools` dependency
-            # only when bootstrapping from sources on Python 3.12
-            if spec_for_current_python() == "python@3.12":
-                concrete_spec.constrain("+force_setuptools")
 
             if module == "clingo":
                 # TODO: remove when the old concretizer is deprecated  # pylint: disable=fixme
@@ -538,6 +534,41 @@ def ensure_patchelf_in_path_or_raise() -> spack.util.executable.Executable:
         )
 
 
+def ensure_winsdk_external_or_raise() -> None:
+    """Ensure the Windows SDK + WGL are available on system
+    If both of these package are found, the Spack user or bootstrap
+    configuration (depending on where Spack is running)
+    will be updated to include all versions and variants detected.
+    If either the WDK or WSDK are not found, this method will raise
+    a RuntimeError.
+
+    **NOTE:** This modifies the Spack config in the current scope,
+    either user or environment depending on the calling context.
+    This is different from all other current bootstrap dependency
+    checks.
+    """
+    if set(["win-sdk", "wgl"]).issubset(spack.config.get("packages").keys()):
+        return
+    externals = spack.detection.by_path(["win-sdk", "wgl"])
+    if not set(["win-sdk", "wgl"]) == externals.keys():
+        missing_packages_lst = []
+        if "wgl" not in externals:
+            missing_packages_lst.append("wgl")
+        if "win-sdk" not in externals:
+            missing_packages_lst.append("win-sdk")
+        missing_packages = " & ".join(missing_packages_lst)
+        raise RuntimeError(
+            f"Unable to find the {missing_packages}, please install these packages \
+via the Visual Studio installer \
+before proceeding with Spack or provide the path to a non standard install with \
+'spack external find --path'"
+        )
+    # wgl/sdk are not required for bootstrapping Spack, but
+    # are required for building anything non trivial
+    # add to user config so they can be used by subsequent Spack ops
+    spack.detection.update_configuration(externals, buildable=False)
+
+
 def ensure_core_dependencies() -> None:
     """Ensure the presence of all the core dependencies."""
     if sys.platform.lower() == "linux":

lib/spack/spack/bootstrap/environment.py

@@ -3,13 +3,11 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 """Bootstrap non-core Spack dependencies from an environment."""
-import glob
 import hashlib
 import os
 import pathlib
 import sys
-import warnings
-from typing import List
+from typing import Iterable, List
 
 import archspec.cpu
 
@@ -28,6 +26,16 @@
 class BootstrapEnvironment(spack.environment.Environment):
     """Environment to install dependencies of Spack for a given interpreter and architecture"""
 
+    def __init__(self) -> None:
+        if not self.spack_yaml().exists():
+            self._write_spack_yaml_file()
+        super().__init__(self.environment_root())
+
+        # Remove python package roots created before python-venv was introduced
+        for s in self.concrete_roots():
+            if "python" in s.package.extendees and not s.dependencies("python-venv"):
+                self.deconcretize(s)
+
     @classmethod
     def spack_dev_requirements(cls) -> List[str]:
         """Spack development requirements"""
@@ -59,31 +67,19 @@ def view_root(cls) -> pathlib.Path:
         return cls.environment_root().joinpath("view")
 
     @classmethod
-    def pythonpaths(cls) -> List[str]:
-        """Paths to be added to sys.path or PYTHONPATH"""
-        python_dir_part = f"python{'.'.join(str(x) for x in sys.version_info[:2])}"
-        glob_expr = str(cls.view_root().joinpath("**", python_dir_part, "**"))
-        result = glob.glob(glob_expr)
-        if not result:
-            msg = f"Cannot find any Python path in {cls.view_root()}"
-            warnings.warn(msg)
-        return result
-
-    @classmethod
-    def bin_dirs(cls) -> List[pathlib.Path]:
+    def bin_dir(cls) -> pathlib.Path:
         """Paths to be added to PATH"""
-        return [cls.view_root().joinpath("bin")]
+        return cls.view_root().joinpath("bin")
+
+    def python_dirs(self) -> Iterable[pathlib.Path]:
+        python = next(s for s in self.all_specs_generator() if s.name == "python-venv").package
+        return {self.view_root().joinpath(p) for p in (python.platlib, python.purelib)}
 
     @classmethod
     def spack_yaml(cls) -> pathlib.Path:
         """Environment spack.yaml file"""
         return cls.environment_root().joinpath("spack.yaml")
 
-    def __init__(self) -> None:
-        if not self.spack_yaml().exists():
-            self._write_spack_yaml_file()
-        super().__init__(self.environment_root())
-
     def update_installations(self) -> None:
         """Update the installations of this environment."""
         log_enabled = tty.is_debug() or tty.is_verbose()
@@ -100,21 +96,13 @@ def update_installations(self) -> None:
                 self.install_all()
                 self.write(regenerate=True)
 
-    def update_syspath_and_environ(self) -> None:
-        """Update ``sys.path`` and the PATH, PYTHONPATH environment variables to point to
-        the environment view.
-        """
-        # Do minimal modifications to sys.path and environment variables. In particular, pay
-        # attention to have the smallest PYTHONPATH / sys.path possible, since that may impact
-        # the performance of the current interpreter
-        sys.path.extend(self.pythonpaths())
-        os.environ["PATH"] = os.pathsep.join(
-            [str(x) for x in self.bin_dirs()] + os.environ.get("PATH", "").split(os.pathsep)
-        )
-        os.environ["PYTHONPATH"] = os.pathsep.join(
-            os.environ.get("PYTHONPATH", "").split(os.pathsep)
-            + [str(x) for x in self.pythonpaths()]
-        )
+    def load(self) -> None:
+        """Update PATH and sys.path."""
+        # Make executables available (shouldn't need PYTHONPATH)
+        os.environ["PATH"] = f"{self.bin_dir()}{os.pathsep}{os.environ.get('PATH', '')}"
+
+        # Spack itself imports pytest
+        sys.path.extend(str(p) for p in self.python_dirs())
 
     def _write_spack_yaml_file(self) -> None:
         tty.msg(
@@ -164,4 +152,4 @@ def ensure_environment_dependencies() -> None:
     _add_externals_if_missing()
     with BootstrapEnvironment() as env:
         env.update_installations()
-        env.update_syspath_and_environ()
+        env.load()

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
@@ -481,10 +482,7 @@ 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 +728,28 @@ 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):

lib/spack/spack/build_systems/cmake.py

@@ -39,16 +39,11 @@ def _maybe_set_python_hints(pkg: spack.package_base.PackageBase, args: List[str]
     """Set the PYTHON_EXECUTABLE, Python_EXECUTABLE, and Python3_EXECUTABLE CMake variables
     if the package has Python as build or link dep and ``find_python_hints`` is set to True. See
     ``find_python_hints`` for context."""
-    if not getattr(pkg, "find_python_hints", False):
+    if not getattr(pkg, "find_python_hints", False) or not pkg.spec.dependencies(
+        "python", dt.BUILD | dt.LINK
+    ):
         return
-    pythons = pkg.spec.dependencies("python", dt.BUILD | dt.LINK)
-    if len(pythons) != 1:
-        return
-    try:
-        python_executable = pythons[0].package.command.path
-    except RuntimeError:
-        return
-
+    python_executable = pkg.spec["python"].command.path
     args.extend(
         [
             CMakeBuilder.define("PYTHON_EXECUTABLE", python_executable),

lib/spack/spack/build_systems/compiler.py

@@ -0,0 +1,144 @@
+# Copyright 2013-2023 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 itertools
+import os
+import pathlib
+import re
+import sys
+from typing import Dict, List, Sequence, Tuple, Union
+
+import llnl.util.tty as tty
+from llnl.util.lang import classproperty
+
+import spack.compiler
+import spack.package_base
+
+# Local "type" for type hints
+Path = Union[str, pathlib.Path]
+
+
+class CompilerPackage(spack.package_base.PackageBase):
+    """A Package mixin for all common logic for packages that implement compilers"""
+
+    # TODO: how do these play nicely with other tags
+    tags: Sequence[str] = ["compiler"]
+
+    #: Optional suffix regexes for searching for this type of compiler.
+    #: Suffixes are used by some frameworks, e.g. macports uses an '-mp-X.Y'
+    #: version suffix for gcc.
+    compiler_suffixes: List[str] = [r"-.*"]
+
+    #: Optional prefix regexes for searching for this compiler
+    compiler_prefixes: List[str] = []
+
+    #: Compiler argument(s) that produces version information
+    #: If multiple arguments, the earlier arguments must produce errors when invalid
+    compiler_version_argument: Union[str, Tuple[str]] = "-dumpversion"
+
+    #: Regex used to extract version from compiler's output
+    compiler_version_regex: str = "(.*)"
+
+    #: Static definition of languages supported by this class
+    compiler_languages: Sequence[str] = ["c", "cxx", "fortran"]
+
+    def __init__(self, spec: "spack.spec.Spec"):
+        super().__init__(spec)
+        msg = f"Supported languages for {spec} are not a subset of possible supported languages"
+        msg += f"    supports: {self.supported_languages}, valid values: {self.compiler_languages}"
+        assert set(self.supported_languages) <= set(self.compiler_languages), msg
+
+    @property
+    def supported_languages(self) -> Sequence[str]:
+        """Dynamic definition of languages supported by this package"""
+        return self.compiler_languages
+
+    @classproperty
+    def compiler_names(cls) -> Sequence[str]:
+        """Construct list of compiler names from per-language names"""
+        names = []
+        for language in cls.compiler_languages:
+            names.extend(getattr(cls, f"{language}_names"))
+        return names
+
+    @classproperty
+    def executables(cls) -> Sequence[str]:
+        """Construct executables for external detection from names, prefixes, and suffixes."""
+        regexp_fmt = r"^({0}){1}({2})$"
+        prefixes = [""] + cls.compiler_prefixes
+        suffixes = [""] + cls.compiler_suffixes
+        if sys.platform == "win32":
+            ext = r"\.(?:exe|bat)"
+            suffixes += [suf + ext for suf in suffixes]
+        return [
+            regexp_fmt.format(prefix, re.escape(name), suffix)
+            for prefix, name, suffix in itertools.product(prefixes, cls.compiler_names, suffixes)
+        ]
+
+    @classmethod
+    def determine_version(cls, exe: Path):
+        version_argument = cls.compiler_version_argument
+        if isinstance(version_argument, str):
+            version_argument = (version_argument,)
+
+        for va in version_argument:
+            try:
+                output = spack.compiler.get_compiler_version_output(exe, va)
+                match = re.search(cls.compiler_version_regex, output)
+                if match:
+                    return ".".join(match.groups())
+            except spack.util.executable.ProcessError:
+                pass
+            except Exception as e:
+                tty.debug(
+                    f"[{__file__}] Cannot detect a valid version for the executable "
+                    f"{str(exe)}, for package '{cls.name}': {e}"
+                )
+
+    @classmethod
+    def compiler_bindir(cls, prefix: Path) -> Path:
+        """Overridable method for the location of the compiler bindir within the preifx"""
+        return os.path.join(prefix, "bin")
+
+    @classmethod
+    def determine_compiler_paths(cls, exes: Sequence[Path]) -> Dict[str, Path]:
+        """Compute the paths to compiler executables associated with this package
+
+        This is a helper method for ``determine_variants`` to compute the ``extra_attributes``
+        to include with each spec object."""
+        # There are often at least two copies (not symlinks) of each compiler executable in the
+        # same directory: one with a canonical name, e.g. "gfortran", and another one with the
+        # target prefix, e.g. "x86_64-pc-linux-gnu-gfortran". There also might be a copy of "gcc"
+        # with the version suffix, e.g. "x86_64-pc-linux-gnu-gcc-6.3.0". To ensure the consistency
+        # of values in the "paths" dictionary (i.e. we prefer all of them to reference copies
+        # with canonical names if possible), we iterate over the executables in the reversed sorted
+        # order:
+        # First pass over languages identifies exes that are perfect matches for canonical names
+        # Second pass checks for names with prefix/suffix
+        # Second pass is sorted by language name length because longer named languages
+        # e.g. cxx can often contain the names of shorter named languages
+        # e.g. c (e.g. clang/clang++)
+        paths = {}
+        exes = sorted(exes, reverse=True)
+        languages = {
+            lang: getattr(cls, f"{lang}_names")
+            for lang in sorted(cls.compiler_languages, key=len, reverse=True)
+        }
+        for exe in exes:
+            for lang, names in languages.items():
+                if os.path.basename(exe) in names:
+                    paths[lang] = exe
+                    break
+            else:
+                for lang, names in languages.items():
+                    if any(name in os.path.basename(exe) for name in names):
+                        paths[lang] = exe
+                        break
+
+        return paths
+
+    @classmethod
+    def determine_variants(cls, exes: Sequence[Path], version_str: str) -> Tuple:
+        # path determination is separated so it can be reused in subclasses
+        return "", {"compilers": cls.determine_compiler_paths(exes=exes)}

lib/spack/spack/build_systems/nmake.py

@@ -145,7 +145,7 @@ 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/python.py

@@ -138,16 +138,21 @@ def view_file_conflicts(self, view, merge_map):
         return conflicts
 
     def add_files_to_view(self, view, merge_map, skip_if_exists=True):
-        # Patch up shebangs to the python linked in the view only if python is built by Spack.
-        if not self.extendee_spec or self.extendee_spec.external:
+        # Patch up shebangs if the package extends Python and we put a Python interpreter in the
+        # view.
+        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.
         copied_files: Dict[Tuple[int, int], str] = {}  # File identifier -> source
         delayed_links: List[Tuple[str, str]] = []  # List of symlinks from merge map
-
         bin_dir = self.spec.prefix.bin
-        python_prefix = self.extendee_spec.prefix
+
         for src, dst in merge_map.items():
             if skip_if_exists and os.path.lexists(dst):
                 continue
@@ -168,7 +173,7 @@ def add_files_to_view(self, view, merge_map, skip_if_exists=True):
                 copied_files[(s.st_dev, s.st_ino)] = dst
                 shutil.copy2(src, dst)
                 fs.filter_file(
-                    python_prefix, os.path.abspath(view.get_projection_for_spec(self.spec)), dst
+                    python.prefix, os.path.abspath(view.get_projection_for_spec(self.spec)), dst
                 )
             else:
                 view.link(src, dst)
@@ -199,14 +204,13 @@ def remove_files_from_view(self, view, merge_map):
                 ignore_namespace = True
 
         bin_dir = self.spec.prefix.bin
-        global_view = self.extendee_spec.prefix == view.get_projection_for_spec(self.spec)
 
         to_remove = []
         for src, dst in merge_map.items():
             if ignore_namespace and namespace_init(dst):
                 continue
 
-            if global_view or not fs.path_contains_subdirectory(src, bin_dir):
+            if not fs.path_contains_subdirectory(src, bin_dir):
                 to_remove.append(dst)
             else:
                 os.remove(dst)
@@ -362,6 +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."""
@@ -371,8 +381,9 @@ def headers(self) -> HeaderList:
 
         # Headers should only be in include or platlib, but no harm in checking purelib too
         include = self.prefix.join(self.spec["python"].package.include).join(name)
-        platlib = self.prefix.join(self.spec["python"].package.platlib).join(name)
-        purelib = self.prefix.join(self.spec["python"].package.purelib).join(name)
+        python = self.python_spec
+        platlib = self.prefix.join(python.package.platlib).join(name)
+        purelib = self.prefix.join(python.package.purelib).join(name)
 
         headers_list = map(fs.find_all_headers, [include, platlib, purelib])
         headers = functools.reduce(operator.add, headers_list)
@@ -391,8 +402,9 @@ def libs(self) -> LibraryList:
         name = self.spec.name[3:]
 
         # Libraries should only be in platlib, but no harm in checking purelib too
-        platlib = self.prefix.join(self.spec["python"].package.platlib).join(name)
-        purelib = self.prefix.join(self.spec["python"].package.purelib).join(name)
+        python = self.python_spec
+        platlib = self.prefix.join(python.package.platlib).join(name)
+        purelib = self.prefix.join(python.package.purelib).join(name)
 
         find_all_libraries = functools.partial(fs.find_all_libraries, recursive=True)
         libs_list = map(find_all_libraries, [platlib, purelib])
@@ -504,6 +516,8 @@ def global_options(self, spec: Spec, prefix: Prefix) -> Iterable[str]:
 
     def install(self, pkg: PythonPackage, spec: Spec, prefix: Prefix) -> None:
         """Install everything from build directory."""
+        pip = spec["python"].command
+        pip.add_default_arg("-m", "pip")
 
         args = PythonPipBuilder.std_args(pkg) + [f"--prefix={prefix}"]
 
@@ -519,14 +533,6 @@ def install(self, pkg: PythonPackage, spec: Spec, prefix: Prefix) -> None:
         else:
             args.append(".")
 
-        pip = spec["python"].command
-        # Hide user packages, since we don't have build isolation. This is
-        # necessary because pip / setuptools may run hooks from arbitrary
-        # packages during the build. There is no equivalent variable to hide
-        # system packages, so this is not reliable for external Python.
-        pip.add_default_env("PYTHONNOUSERSITE", "1")
-        pip.add_default_arg("-m")
-        pip.add_default_arg("pip")
         with fs.working_dir(self.build_directory):
             pip(*args)
 

lib/spack/spack/ci.py

@@ -44,6 +44,7 @@
 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
@@ -683,6 +684,22 @@ 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 +823,7 @@ 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 +1244,9 @@ 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:
@@ -1283,7 +1303,6 @@ 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)
@@ -1478,6 +1497,12 @@ 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 +1525,7 @@ 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 +1967,9 @@ 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 +2201,13 @@ 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 +2273,7 @@ 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 +2319,7 @@ 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/cmd/audit.py

@@ -84,7 +84,7 @@ def externals(parser, args):
         return
 
     pkgs = args.name or spack.repo.PATH.all_package_names()
-    reports = spack.audit.run_group(args.subcommand, pkgs=pkgs)
+    reports = spack.audit.run_group(args.subcommand, pkgs=pkgs, debug_log=tty.debug)
     _process_reports(reports)
 
 

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

@@ -31,7 +31,6 @@
 level = "long"
 
 SPACK_COMMAND = "spack"
-MAKE_COMMAND = "make"
 INSTALL_FAIL_CODE = 1
 FAILED_CREATE_BUILDCACHE_CODE = 100
 
@@ -40,6 +39,12 @@ 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")
@@ -551,75 +556,35 @@ 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/common/arguments.py

@@ -563,12 +563,13 @@ def add_concretizer_args(subparser):
         help="reuse installed packages/buildcaches when possible",
     )
     subgroup.add_argument(
+        "--fresh-roots",
         "--reuse-deps",
         action=ConfigSetAction,
         dest="concretizer:reuse",
         const="dependencies",
         default=None,
-        help="reuse installed dependencies only",
+        help="concretize with fresh roots and reused dependencies",
     )
     subgroup.add_argument(
         "--deprecated",

lib/spack/spack/cmd/env.py

@@ -10,13 +10,13 @@
 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
 import llnl.util.tty as tty
 from llnl.util.tty.colify import colify
-from llnl.util.tty.color import colorize
+from llnl.util.tty.color import cescape, colorize
 
 import spack.cmd
 import spack.cmd.common
@@ -61,14 +61,7 @@
 #
 def env_create_setup_parser(subparser):
     """create a new environment"""
-    subparser.add_argument(
-        "env_name",
-        metavar="env",
-        help=(
-            "name of managed environment or directory of the anonymous env "
-            "(when using --dir/-d) to activate"
-        ),
-    )
+    subparser.add_argument("env_name", metavar="env", help="name or directory of environment")
     subparser.add_argument(
         "-d", "--dir", action="store_true", help="create an environment in a specific directory"
     )
@@ -94,6 +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):
@@ -111,19 +107,32 @@ 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,
+        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.
     env.regenerate_views()
 
 
-def _env_create(name_or_path, *, init_file=None, dir=False, with_view=None, keep_relative=False):
+def _env_create(
+    name_or_path: str,
+    *,
+    init_file: Optional[str] = None,
+    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:
@@ -135,22 +144,31 @@ def _env_create(name_or_path, *, init_file=None, dir=False, with_view=None, keep
         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("Created environment '%s' in %s" % (name_or_path, env.path))
-        tty.msg("You can activate this environment with:")
-        tty.msg("  spack env activate %s" % (name_or_path))
-        return env
-
-    env = ev.create_in_dir(
-        name_or_path, init_file=init_file, with_view=with_view, keep_relative=keep_relative
-    )
-    tty.msg("Created environment in %s" % env.path)
-    tty.msg("You can activate this environment with:")
-    tty.msg("  spack env activate %s" % env.path)
+        tty.msg(
+            colorize(
+                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,
+            include_concrete=include_concrete,
+        )
+        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
 
 
@@ -436,6 +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):
@@ -445,13 +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/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/unit_test.py

@@ -214,8 +214,6 @@ def unit_test(parser, args, unknown_args):
 
     # Ensure clingo is available before switching to the
     # mock configuration used by unit tests
-    # Note: skip on windows here because for the moment,
-    # clingo is wholly unsupported from bootstrap
     with spack.bootstrap.ensure_bootstrap_configuration():
         spack.bootstrap.ensure_core_dependencies()
         if pytest is None:

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

@@ -20,6 +20,7 @@
 
 import spack.compilers
 import spack.error
+import spack.schema.environment
 import spack.spec
 import spack.util.executable
 import spack.util.libc
@@ -683,8 +684,8 @@ def __str__(self):
 
     @contextlib.contextmanager
     def compiler_environment(self):
-        # yield immediately if no modules
-        if not self.modules:
+        # Avoid modifying os.environ if possible.
+        if not self.modules and not self.environment:
             yield
             return
 
@@ -701,13 +702,9 @@ def compiler_environment(self):
                 spack.util.module_cmd.load_module(module)
 
             # apply other compiler environment changes
-            env = spack.util.environment.EnvironmentModifications()
-            env.extend(spack.schema.environment.parse(self.environment))
-            env.apply_modifications()
+            spack.schema.environment.parse(self.environment).apply_modifications()
 
             yield
-        except BaseException:
-            raise
         finally:
             # Restore environment regardless of whether inner code succeeded
             os.environ.clear()

lib/spack/spack/compilers/__init__.py

@@ -164,43 +164,66 @@ def _compiler_config_from_package_config(config):
 
 
 def _compiler_config_from_external(config):
+    extra_attributes_key = "extra_attributes"
+    compilers_key = "compilers"
+    c_key, cxx_key, fortran_key = "c", "cxx", "fortran"
+
+    # Allow `@x.y.z` instead of `@=x.y.z`
     spec = spack.spec.parse_with_version_concrete(config["spec"])
-    # use str(spec.versions) to allow `@x.y.z` instead of `@=x.y.z`
+
     compiler_spec = spack.spec.CompilerSpec(
         package_name_to_compiler_name.get(spec.name, spec.name), spec.version
     )
 
-    extra_attributes = config.get("extra_attributes", {})
-    prefix = config.get("prefix", None)
+    err_header = f"The external spec '{spec}' cannot be used as a compiler"
 
-    compiler_class = class_for_compiler_name(compiler_spec.name)
-    paths = extra_attributes.get("paths", {})
-    compiler_langs = ["cc", "cxx", "fc", "f77"]
-    for lang in compiler_langs:
-        if paths.setdefault(lang, None):
-            continue
-
-        if not prefix:
-            continue
-
-        # Check for files that satisfy the naming scheme for this compiler
-        bindir = os.path.join(prefix, "bin")
-        for f, regex in itertools.product(os.listdir(bindir), compiler_class.search_regexps(lang)):
-            if regex.match(f):
-                paths[lang] = os.path.join(bindir, f)
-
-    if all(v is None for v in paths.values()):
+    # If extra_attributes is not there I might not want to use this entry as a compiler,
+    # therefore just leave a debug message, but don't be loud with a warning.
+    if extra_attributes_key not in config:
+        tty.debug(f"[{__file__}] {err_header}: missing the '{extra_attributes_key}' key")
         return None
+    extra_attributes = config[extra_attributes_key]
+
+    # If I have 'extra_attributes' warn if 'compilers' is missing, or we don't have a C compiler
+    if compilers_key not in extra_attributes:
+        warnings.warn(
+            f"{err_header}: missing the '{compilers_key}' key under '{extra_attributes_key}'"
+        )
+        return None
+    attribute_compilers = extra_attributes[compilers_key]
+
+    if c_key not in attribute_compilers:
+        warnings.warn(
+            f"{err_header}: missing the C compiler path under "
+            f"'{extra_attributes_key}:{compilers_key}'"
+        )
+        return None
+    c_compiler = attribute_compilers[c_key]
+
+    # C++ and Fortran compilers are not mandatory, so let's just leave a debug trace
+    if cxx_key not in attribute_compilers:
+        tty.debug(f"[{__file__}] The external spec {spec} does not have a C++ compiler")
+
+    if fortran_key not in attribute_compilers:
+        tty.debug(f"[{__file__}] The external spec {spec} does not have a Fortran compiler")
+
+    # compilers format has cc/fc/f77, externals format has "c/fortran"
+    paths = {
+        "cc": c_compiler,
+        "cxx": attribute_compilers.get(cxx_key, None),
+        "fc": attribute_compilers.get(fortran_key, None),
+        "f77": attribute_compilers.get(fortran_key, None),
+    }
 
     if not spec.architecture:
         host_platform = spack.platforms.host()
         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/concretize.py

@@ -74,6 +74,10 @@ class Concretizer:
     #: during concretization. Used for testing and for mirror creation
     check_for_compiler_existence = None
 
+    #: Packages that the old concretizer cannot deal with correctly, and cannot build anyway.
+    #: Those will not be considered as providers for virtuals.
+    non_buildable_packages = {"glibc", "musl"}
+
     def __init__(self, abstract_spec=None):
         if Concretizer.check_for_compiler_existence is None:
             Concretizer.check_for_compiler_existence = not spack.config.get(
@@ -113,7 +117,11 @@ def _valid_virtuals_and_externals(self, spec):
         pref_key = lambda spec: 0  # no-op pref key
 
         if spec.virtual:
-            candidates = spack.repo.PATH.providers_for(spec)
+            candidates = [
+                s
+                for s in spack.repo.PATH.providers_for(spec)
+                if s.name not in self.non_buildable_packages
+            ]
             if not candidates:
                 raise spack.error.UnsatisfiableProviderSpecError(candidates[0], spec)
 

lib/spack/spack/container/images.json

@@ -34,28 +34,6 @@
         "image": "docker.io/fedora:39"
       }
     },
-    "fedora:38": {
-      "bootstrap": {
-        "template": "container/fedora.dockerfile",
-        "image": "docker.io/fedora:38"
-      },
-      "os_package_manager": "dnf",
-      "build": "spack/fedora38",
-      "final": {
-        "image": "docker.io/fedora:38"
-      }
-    },
-    "fedora:37": {
-      "bootstrap": {
-        "template": "container/fedora.dockerfile",
-        "image": "docker.io/fedora:37"
-      },
-      "os_package_manager": "dnf",
-      "build": "spack/fedora37",
-      "final": {
-        "image": "docker.io/fedora:37"
-      }
-    },
     "rockylinux:9": {
       "bootstrap": {
         "template": "container/rockylinux_9.dockerfile",
@@ -138,6 +116,13 @@
       },
       "os_package_manager": "apt"
     },
+    "ubuntu:24.04": {
+      "bootstrap": {
+        "template": "container/ubuntu_2404.dockerfile"
+      },
+      "os_package_manager": "apt",
+      "build": "spack/ubuntu-noble"
+    },
     "ubuntu:22.04": {
       "bootstrap": {
         "template": "container/ubuntu_2204.dockerfile"
@@ -151,13 +136,6 @@
       },
       "build": "spack/ubuntu-focal",
       "os_package_manager": "apt"
-    },
-    "ubuntu:18.04": {
-      "bootstrap": {
-        "template": "container/ubuntu_1804.dockerfile"
-      },
-      "os_package_manager": "apt",
-      "build": "spack/ubuntu-bionic"
     }
   },
   "os_package_managers": {

lib/spack/spack/directives.py

@@ -662,6 +662,7 @@ def _execute_redistribute(
 @directive(("extendees", "dependencies"))
 def extends(spec, when=None, type=("build", "run"), patches=None):
     """Same as depends_on, but also adds this package to the extendee list.
+    In case of Python, also adds a dependency on python-venv.
 
     keyword arguments can be passed to extends() so that extension
     packages can pass parameters to the extendee's extension
@@ -677,6 +678,11 @@ def _execute_extends(pkg):
         _depends_on(pkg, spec, when=when, type=type, patches=patches)
         spec_obj = spack.spec.Spec(spec)
 
+        # When extending python, also add a dependency on python-venv. This is done so that
+        # Spack environment views are Python virtual environments.
+        if spec_obj.name == "python" and not pkg.name == "python-venv":
+            _depends_on(pkg, "python-venv", when=when, type=("build", "run"))
+
         # TODO: the values of the extendees dictionary are not used. Remove in next refactor.
         pkg.extendees[spec_obj.name] = (spec_obj, None)
 

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

@@ -16,13 +16,13 @@
 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.compilers
 import spack.concretize
@@ -30,6 +30,7 @@
 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 +53,6 @@
 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 +159,8 @@ 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 +295,7 @@ 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 +312,15 @@ 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 +329,7 @@ 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 +343,7 @@ 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 +356,12 @@ 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 +435,67 @@ 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 +606,7 @@ 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 +640,7 @@ 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 +662,7 @@ 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 +690,7 @@ 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 +710,14 @@ 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 +898,18 @@ 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 +947,7 @@ 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 +1015,20 @@ 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 +1045,31 @@ 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 +1094,26 @@ 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 +1125,15 @@ 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 +1187,55 @@ 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 +1435,10 @@ 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)
@@ -1415,7 +1622,7 @@ def _concretize_separately(self, tests=False):
         # Ensure we don't try to bootstrap clingo in parallel
         if spack.config.get("config:concretizer", "clingo") == "clingo":
             with spack.bootstrap.ensure_bootstrap_configuration():
-                spack.bootstrap.ensure_core_dependencies()
+                spack.bootstrap.ensure_clingo_importable_or_raise()
 
         # Ensure all the indexes have been built or updated, since
         # otherwise the processes in the pool may timeout on waiting
@@ -1704,8 +1911,14 @@ 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=*")
                 ):
@@ -1785,8 +1998,14 @@ 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 +2134,7 @@ 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 +2179,76 @@ 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 +2261,39 @@ 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 +2316,8 @@ 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 +2325,10 @@ 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 +2341,7 @@ 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()
@@ -2545,6 +2840,19 @@ 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 +3036,56 @@ 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/autopush.py

@@ -12,6 +12,10 @@
 def post_install(spec, explicit):
     # Push package to all buildcaches with autopush==True
 
+    # Do nothing if spec is an external package
+    if spec.external:
+        return
+
     # Do nothing if package was not installed from source
     pkg = spec.package
     if pkg.installed_from_binary_cache:

lib/spack/spack/hooks/windows_runtime_linkage.py

@@ -0,0 +1,8 @@
+# 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)
+
+
+def post_install(spec, explicit=None):
+    spec.package.windows_establish_runtime_linkage()

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()
@@ -1698,10 +1699,6 @@ def _install_task(self, task: BuildTask, install_status: InstallStatus) -> None:
             spack.package_base.PackageBase._verbose = spack.build_environment.start_build_process(
                 pkg, build_process, install_args
             )
-            # Currently this is how RPATH-like behavior is achieved on Windows, after install
-            # establish runtime linkage via Windows Runtime link object
-            # Note: this is a no-op on non Windows platforms
-            pkg.windows_establish_runtime_linkage()
             # Note: PARENT of the build process adds the new package to
             # the database, so that we don't need to re-read from file.
             spack.store.STORE.db.add(pkg.spec, spack.store.STORE.layout, explicit=explicit)

lib/spack/spack/main.py

@@ -427,7 +427,7 @@ def make_argument_parser(**kwargs):
     parser.add_argument(
         "--color",
         action="store",
-        default=os.environ.get("SPACK_COLOR", "auto"),
+        default=None,
         choices=("always", "never", "auto"),
         help="when to colorize output (default: auto)",
     )
@@ -622,7 +622,8 @@ def setup_main_options(args):
     # with color
     color.try_enable_terminal_color_on_windows()
     # when to use color (takes always, auto, or never)
-    color.set_color_when(args.color)
+    if args.color is not None:
+        color.set_color_when(args.color)
 
 
 def allows_unknown_args(command):

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

@@ -398,7 +398,7 @@ def create_opener():
     opener = urllib.request.OpenerDirector()
     for handler in [
         urllib.request.UnknownHandler(),
-        urllib.request.HTTPSHandler(),
+        urllib.request.HTTPSHandler(context=spack.util.web.ssl_create_default_context()),
         spack.util.web.SpackHTTPDefaultErrorHandler(),
         urllib.request.HTTPRedirectHandler(),
         urllib.request.HTTPErrorProcessor(),
@@ -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/package.py

@@ -39,6 +39,7 @@
 )
 from spack.build_systems.cargo import CargoPackage
 from spack.build_systems.cmake import CMakePackage, generator
+from spack.build_systems.compiler import CompilerPackage
 from spack.build_systems.cuda import CudaPackage
 from spack.build_systems.generic import Package
 from spack.build_systems.gnu import GNUMirrorPackage

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()
@@ -1115,10 +1119,9 @@ 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 +1243,7 @@ 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 +1450,8 @@ 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 +1558,11 @@ 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.
@@ -1898,7 +1897,7 @@ 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 +2445,18 @@ 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))
@@ -2555,7 +2563,12 @@ class PackageStillNeededError(InstallError):
     """Raised when package is still needed by another on uninstall."""
 
     def __init__(self, spec, dependents):
-        super().__init__("Cannot uninstall %s" % spec)
+        spec_fmt = spack.spec.DEFAULT_FORMAT + " /{hash:7}"
+        dep_fmt = "{name}{@versions} /{hash:7}"
+        super().__init__(
+            f"Cannot uninstall {spec.format(spec_fmt)}, "
+            f"needed by {[dep.format(dep_fmt) for dep in dependents]}"
+        )
         self.spec = spec
         self.dependents = dependents
 

lib/spack/spack/platforms/cray.py

@@ -10,6 +10,7 @@
 import archspec.cpu
 
 import llnl.util.tty as tty
+from llnl.util.symlink import readlink
 
 import spack.target
 import spack.version
@@ -133,7 +134,7 @@ def craype_type_and_version(cls):
         # 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))
+            version = spack.version.Version(readlink(default_path))
             return (craype_type, version)
 
         # If no default version, sort available versions and return latest

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

@@ -27,7 +27,7 @@
 from spack.error import SpackError
 from spack.util.crypto import checksum
 from spack.util.log_parse import parse_log_events
-from spack.util.web import urllib_ssl_cert_handler
+from spack.util.web import ssl_create_default_context
 
 from .base import Reporter
 from .extract import extract_test_parts
@@ -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"]
@@ -428,7 +429,7 @@ def upload(self, filename):
         # Compute md5 checksum for the contents of this file.
         md5sum = checksum(hashlib.md5, filename, block_size=8192)
 
-        opener = build_opener(HTTPSHandler(context=urllib_ssl_cert_handler()))
+        opener = build_opener(HTTPSHandler(context=ssl_create_default_context()))
         with open(filename, "rb") as f:
             params_dict = {
                 "build": self.buildname,
@@ -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/concretizer.py

@@ -9,13 +9,40 @@
 """
 from typing import Any, Dict
 
+LIST_OF_SPECS = {"type": "array", "items": {"type": "string"}}
+
 properties: Dict[str, Any] = {
     "concretizer": {
         "type": "object",
         "additionalProperties": False,
         "properties": {
             "reuse": {
-                "oneOf": [{"type": "boolean"}, {"type": "string", "enum": ["dependencies"]}]
+                "oneOf": [
+                    {"type": "boolean"},
+                    {"type": "string", "enum": ["dependencies"]},
+                    {
+                        "type": "object",
+                        "properties": {
+                            "roots": {"type": "boolean"},
+                            "include": LIST_OF_SPECS,
+                            "exclude": LIST_OF_SPECS,
+                            "from": {
+                                "type": "array",
+                                "items": {
+                                    "type": "object",
+                                    "properties": {
+                                        "type": {
+                                            "type": "string",
+                                            "enum": ["local", "buildcache", "external"],
+                                        },
+                                        "include": LIST_OF_SPECS,
+                                        "exclude": LIST_OF_SPECS,
+                                    },
+                                },
+                            },
+                        },
+                    },
+                ]
             },
             "enable_node_namespace": {"type": "boolean"},
             "targets": {

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

@@ -6,6 +6,7 @@
 import collections.abc
 import copy
 import enum
+import functools
 import itertools
 import os
 import pathlib
@@ -313,6 +314,10 @@ 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.
 
@@ -808,12 +813,22 @@ def solve(self, setup, specs, reuse=None, output=None, control=None, allow_depre
             A tuple of the solve result, the timer for the different phases of the
             solve, and the internal statistics from clingo.
         """
+        # avoid circular import
+        import spack.bootstrap
+
         output = output or DEFAULT_OUTPUT_CONFIGURATION
         timer = spack.util.timer.Timer()
 
         # Initialize the control object for the solver
         self.control = control or default_clingo_control()
 
+        # ensure core deps are present on Windows
+        # needs to modify active config scope, so cannot be run within
+        # bootstrap config scope
+        if sys.platform == "win32":
+            tty.debug("Ensuring basic dependencies {win-sdk, wgl} available")
+            spack.bootstrap.core.ensure_winsdk_external_or_raise()
+
         timer.start("setup")
         asp_problem = setup.setup(specs, reuse=reuse, allow_deprecated=allow_deprecated)
         if output.out is not None:
@@ -829,8 +844,6 @@ 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"))
@@ -933,14 +946,26 @@ class ConcreteSpecsByHash(collections.abc.Mapping):
 
     def __init__(self) -> None:
         self.data: Dict[str, spack.spec.Spec] = {}
+        self.explicit: Set[str] = set()
 
     def __getitem__(self, dag_hash: str) -> spack.spec.Spec:
         return self.data[dag_hash]
 
+    def explicit_items(self) -> Iterator[Tuple[str, spack.spec.Spec]]:
+        """Iterate on items that have been added explicitly, and not just as a dependency
+        of other nodes.
+        """
+        for h, s in self.items():
+            # We need to make an exception for gcc-runtime, until we can splice it.
+            if h in self.explicit or s.name == "gcc-runtime":
+                yield h, s
+
     def add(self, spec: spack.spec.Spec) -> bool:
         """Adds a new concrete spec to the mapping. Returns True if the spec was just added,
         False if the spec was already in the mapping.
 
+        Calling this function marks the spec as added explicitly.
+
         Args:
             spec: spec to be added
 
@@ -955,6 +980,7 @@ def add(self, spec: spack.spec.Spec) -> bool:
             raise ValueError(msg)
 
         dag_hash = spec.dag_hash()
+        self.explicit.add(dag_hash)
         if dag_hash in self.data:
             return False
 
@@ -1221,6 +1247,9 @@ def pkg_rules(self, pkg, tests):
 
     def trigger_rules(self):
         """Flushes all the trigger rules collected so far, and clears the cache."""
+        if not self._trigger_cache:
+            return
+
         self.gen.h2("Trigger conditions")
         for name in self._trigger_cache:
             cache = self._trigger_cache[name]
@@ -1234,6 +1263,9 @@ def trigger_rules(self):
 
     def effect_rules(self):
         """Flushes all the effect rules collected so far, and clears the cache."""
+        if not self._effect_cache:
+            return
+
         self.gen.h2("Imposed requirements")
         for name in self._effect_cache:
             cache = self._effect_cache[name]
@@ -1396,7 +1428,6 @@ def condition(
             raise ValueError(f"Must provide a name for anonymous condition: '{required_spec}'")
 
         with spec_with_name(required_spec, name):
-
             # Check if we can emit the requirements before updating the condition ID counter.
             # In this way, if a condition can't be emitted but the exception is handled in the
             # caller, we won't emit partial facts.
@@ -1614,6 +1645,31 @@ def external_packages(self):
         packages_yaml = _external_config_with_implicit_externals(spack.config.CONFIG)
 
         self.gen.h1("External packages")
+        spec_filters = []
+        concretizer_yaml = spack.config.get("concretizer")
+        reuse_yaml = concretizer_yaml.get("reuse")
+        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(
+                        factory=lambda: [],
+                        is_usable=lambda x: True,
+                        include=include,
+                        exclude=exclude,
+                    )
+                )
+
         for pkg_name, data in packages_yaml.items():
             if pkg_name == "all":
                 continue
@@ -1622,7 +1678,6 @@ def external_packages(self):
             if pkg_name not in spack.repo.PATH:
                 continue
 
-            self.gen.h2("External package: {0}".format(pkg_name))
             # Check if the external package is buildable. If it is
             # not then "external(<pkg>)" is a fact, unless we can
             # reuse an already installed spec.
@@ -1632,7 +1687,17 @@ def external_packages(self):
 
             # Read a list of all the specs for this package
             externals = data.get("externals", [])
-            external_specs = [spack.spec.parse_with_version_concrete(x["spec"]) for x in externals]
+            candidate_specs = [
+                spack.spec.parse_with_version_concrete(x["spec"]) for x in externals
+            ]
+
+            external_specs = []
+            if spec_filters:
+                for current_filter in spec_filters:
+                    current_filter.factory = lambda: candidate_specs
+                    external_specs.extend(current_filter.selected_specs())
+            else:
+                external_specs.extend(candidate_specs)
 
             # Order the external versions to prefer more recent versions
             # even if specs in packages.yaml are not ordered that way
@@ -1813,11 +1878,8 @@ 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
@@ -1872,6 +1934,11 @@ 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)
@@ -2026,7 +2093,7 @@ def _supported_targets(self, compiler_name, compiler_version, targets):
             try:
                 with warnings.catch_warnings():
                     warnings.simplefilter("ignore")
-                    target.optimization_flags(compiler_name, compiler_version)
+                    target.optimization_flags(compiler_name, str(compiler_version))
                 supported.append(target)
             except archspec.cpu.UnsupportedMicroarchitecture:
                 continue
@@ -2303,7 +2370,7 @@ def register_concrete_spec(self, spec, possible):
 
     def concrete_specs(self):
         """Emit facts for reusable specs"""
-        for h, spec in self.reusable_and_possible.items():
+        for h, spec in self.reusable_and_possible.explicit_items():
             # this indicates that there is a spec like this installed
             self.gen.fact(fn.installed_hash(spec.name, h))
             # this describes what constraints it imposes on the solve
@@ -2667,7 +2734,7 @@ class _Head:
     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:
@@ -2684,7 +2751,7 @@ class _Body:
     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:
@@ -2912,6 +2979,13 @@ 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 "
@@ -3151,6 +3225,39 @@ 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.
@@ -3187,13 +3294,16 @@ class SpecBuilder:
                 r"^.*_propagate$",
                 r"^.*_satisfies$",
                 r"^.*_set$",
+                r"^compatible_libc$",
                 r"^dependency_holds$",
+                r"^external_conditions_hold$",
                 r"^node_compiler$",
                 r"^package_hash$",
                 r"^root$",
                 r"^track_dependencies$",
                 r"^variant_default_value_from_cli$",
                 r"^virtual_node$",
+                r"^virtual_on_incoming_edges$",
                 r"^virtual_root$",
             ]
         )
@@ -3564,25 +3674,165 @@ def _has_runtime_dependencies(spec: spack.spec.Spec) -> bool:
     return True
 
 
+class SpecFilter:
+    """Given a method to produce a list of specs, this class can filter them according to
+    different criteria.
+    """
+
+    def __init__(
+        self,
+        factory: Callable[[], List[spack.spec.Spec]],
+        is_usable: Callable[[spack.spec.Spec], bool],
+        include: List[str],
+        exclude: List[str],
+    ) -> None:
+        """
+        Args:
+            factory: factory to produce a list of specs
+            is_usable: predicate that takes a spec in input and returns False if the spec
+                should not be considered for this filter, True otherwise.
+            include: if present, a "good" spec must match at least one entry in the list
+            exclude: if present, a "good" spec must not match any entry in the list
+        """
+        self.factory = factory
+        self.is_usable = is_usable
+        self.include = include
+        self.exclude = exclude
+
+    def is_selected(self, s: spack.spec.Spec) -> bool:
+        if not self.is_usable(s):
+            return False
+
+        if self.include and not any(s.satisfies(c) for c in self.include):
+            return False
+
+        if self.exclude and any(s.satisfies(c) for c in self.exclude):
+            return False
+
+        return True
+
+    def selected_specs(self) -> List[spack.spec.Spec]:
+        return [s for s in self.factory() if self.is_selected(s)]
+
+    @staticmethod
+    def from_store(configuration, include, exclude) -> "SpecFilter":
+        """Constructs a filter that takes the specs from the current store."""
+        packages = _external_config_with_implicit_externals(configuration)
+        is_reusable = functools.partial(_is_reusable, packages=packages, local=True)
+        factory = functools.partial(_specs_from_store, configuration=configuration)
+        return SpecFilter(factory=factory, is_usable=is_reusable, include=include, exclude=exclude)
+
+    @staticmethod
+    def from_buildcache(configuration, include, exclude) -> "SpecFilter":
+        """Constructs a filter that takes the specs from the configured buildcaches."""
+        packages = _external_config_with_implicit_externals(configuration)
+        is_reusable = functools.partial(_is_reusable, packages=packages, local=False)
+        return SpecFilter(
+            factory=_specs_from_mirror, is_usable=is_reusable, include=include, exclude=exclude
+        )
+
+
+def _specs_from_store(configuration):
+    store = spack.store.create(configuration)
+    with store.db.read_transaction():
+        return store.db.query(installed=True)
+
+
+def _specs_from_mirror():
+    try:
+        return spack.binary_distribution.update_cache_and_get_specs()
+    except (spack.binary_distribution.FetchCacheError, IndexError):
+        # this is raised when no mirrors had indices.
+        # TODO: update mirror configuration so it can indicate that the
+        # TODO: source cache (or any mirror really) doesn't have binaries.
+        return []
+
+
+class ReuseStrategy(enum.Enum):
+    ROOTS = enum.auto()
+    DEPENDENCIES = enum.auto()
+    NONE = enum.auto()
+
+
+class ReusableSpecsSelector:
+    """Selects specs that can be reused during concretization."""
+
+    def __init__(self, configuration: spack.config.Configuration) -> None:
+        self.configuration = configuration
+        self.store = spack.store.create(configuration)
+        self.reuse_strategy = ReuseStrategy.ROOTS
+
+        reuse_yaml = self.configuration.get("concretizer:reuse", False)
+        self.reuse_sources = []
+        if not isinstance(reuse_yaml, typing.Mapping):
+            if reuse_yaml is False:
+                self.reuse_strategy = ReuseStrategy.NONE
+            if reuse_yaml == "dependencies":
+                self.reuse_strategy = ReuseStrategy.DEPENDENCIES
+            self.reuse_sources.extend(
+                [
+                    SpecFilter.from_store(
+                        configuration=self.configuration, include=[], exclude=[]
+                    ),
+                    SpecFilter.from_buildcache(
+                        configuration=self.configuration, include=[], exclude=[]
+                    ),
+                ]
+            )
+        else:
+            roots = reuse_yaml.get("roots", True)
+            if roots is True:
+                self.reuse_strategy = ReuseStrategy.ROOTS
+            else:
+                self.reuse_strategy = ReuseStrategy.DEPENDENCIES
+            default_include = reuse_yaml.get("include", [])
+            default_exclude = reuse_yaml.get("exclude", [])
+            default_sources = [{"type": "local"}, {"type": "buildcache"}]
+            for source in reuse_yaml.get("from", default_sources):
+                include = source.get("include", default_include)
+                exclude = source.get("exclude", default_exclude)
+                if source["type"] == "local":
+                    self.reuse_sources.append(
+                        SpecFilter.from_store(self.configuration, include=include, exclude=exclude)
+                    )
+                elif source["type"] == "buildcache":
+                    self.reuse_sources.append(
+                        SpecFilter.from_buildcache(
+                            self.configuration, include=include, exclude=exclude
+                        )
+                    )
+
+    def reusable_specs(self, specs: List[spack.spec.Spec]) -> List[spack.spec.Spec]:
+        if self.reuse_strategy == ReuseStrategy.NONE:
+            return []
+
+        result = []
+        for reuse_source in self.reuse_sources:
+            result.extend(reuse_source.selected_specs())
+
+        # If we only want to reuse dependencies, remove the root specs
+        if self.reuse_strategy == ReuseStrategy.DEPENDENCIES:
+            result = [spec for spec in result if not any(root in spec for root in specs)]
+
+        return result
+
+
 class Solver:
     """This is the main external interface class for solving.
 
     It manages solver configuration and preferences in one place. It sets up the solve
     and passes the setup method to the driver, as well.
-
-    Properties of interest:
-
-      ``reuse (bool)``
-        Whether to try to reuse existing installs/binaries
-
     """
 
     def __init__(self):
         self.driver = PyclingoDriver()
-
-        # These properties are settable via spack configuration, and overridable
-        # by setting them directly as properties.
-        self.reuse = spack.config.get("concretizer:reuse", True)
+        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):
@@ -3596,39 +3846,6 @@ def _check_input_and_extract_concrete_specs(specs):
                 spack.spec.Spec.ensure_valid_variants(s)
         return reusable
 
-    def _reusable_specs(self, specs):
-        reusable_specs = []
-        if self.reuse:
-            packages = _external_config_with_implicit_externals(spack.config.CONFIG)
-            # Specs from the local Database
-            with spack.store.STORE.db.read_transaction():
-                reusable_specs.extend(
-                    s
-                    for s in spack.store.STORE.db.query(installed=True)
-                    if _is_reusable(s, packages, local=True)
-                )
-
-            # Specs from buildcaches
-            try:
-                reusable_specs.extend(
-                    s
-                    for s in spack.binary_distribution.update_cache_and_get_specs()
-                    if _is_reusable(s, packages, local=False)
-                )
-            except (spack.binary_distribution.FetchCacheError, IndexError):
-                # this is raised when no mirrors had indices.
-                # TODO: update mirror configuration so it can indicate that the
-                # TODO: source cache (or any mirror really) doesn't have binaries.
-                pass
-
-        # If we only want to reuse dependencies, remove the root specs
-        if self.reuse == "dependencies":
-            reusable_specs = [
-                spec for spec in reusable_specs if not any(root in spec for root in specs)
-            ]
-
-        return reusable_specs
-
     def solve(
         self,
         specs,
@@ -3654,7 +3871,7 @@ def solve(
         # Check upfront that the variants are admissible
         specs = [s.lookup_hash() for s in specs]
         reusable_specs = self._check_input_and_extract_concrete_specs(specs)
-        reusable_specs.extend(self._reusable_specs(specs))
+        reusable_specs.extend(self.selector.reusable_specs(specs))
         setup = SpackSolverSetup(tests=tests)
         output = OutputConfiguration(timers=timers, stats=stats, out=out, setup_only=setup_only)
         result, _, _ = self.driver.solve(
@@ -3683,7 +3900,7 @@ def solve_in_rounds(
         """
         specs = [s.lookup_hash() for s in specs]
         reusable_specs = self._check_input_and_extract_concrete_specs(specs)
-        reusable_specs.extend(self._reusable_specs(specs))
+        reusable_specs.extend(self.selector.reusable_specs(specs))
         setup = SpackSolverSetup(tests=tests)
 
         # Tell clingo that we don't have to solve all the inputs at once

lib/spack/spack/solver/concretize.lp

@@ -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 +958,67 @@ 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 an attribute along edges to child nodes
+propagate(ChildNode, PropagatedAttribute) :-
+  propagate(ParentNode, PropagatedAttribute),
+  depends_on(ParentNode, ChildNode).
+
+%-----------------------------------------------------------------------------
+% 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)).
+
+%----
+% 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 +1120,15 @@ 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 +1190,12 @@ 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),
@@ -1345,8 +1380,10 @@ 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 +1431,16 @@ 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 +1452,6 @@ 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 +1459,7 @@ opt_criterion(73, "deprecated versions used").
 #minimize{
     1@73+Priority,PackageNode
     : attr("deprecated", PackageNode, _),
+      not external(PackageNode),
       build_priority(PackageNode, Priority)
 }.
 
@@ -1431,11 +1467,11 @@ 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 +1531,7 @@ 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 +1541,7 @@ 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 +1561,14 @@ 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/core.py

@@ -195,7 +195,7 @@ def _bootstrap_clingo() -> ModuleType:
     import spack.bootstrap
 
     with spack.bootstrap.ensure_bootstrap_configuration():
-        spack.bootstrap.ensure_core_dependencies()
+        spack.bootstrap.ensure_clingo_importable_or_raise()
         clingo_mod = importlib.import_module("clingo")
 
     return clingo_mod

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

@@ -10,15 +10,13 @@
 %=============================================================================
 
 % 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")).

lib/spack/spack/spec.py

@@ -1030,16 +1030,13 @@ def clear(self):
         self.edges.clear()
 
 
-def _command_default_handler(descriptor, spec, cls):
+def _command_default_handler(spec: "Spec"):
     """Default handler when looking for the 'command' attribute.
 
     Tries to search for ``spec.name`` in the ``spec.home.bin`` directory.
 
     Parameters:
-        descriptor (ForwardQueryToPackage): descriptor that triggered the call
-        spec (Spec): spec that is being queried
-        cls (type(spec)): type of spec, to match the signature of the
-            descriptor ``__get__`` method
+        spec: spec that is being queried
 
     Returns:
         Executable: An executable of the command
@@ -1052,22 +1049,17 @@ def _command_default_handler(descriptor, spec, cls):
 
     if fs.is_exe(path):
         return spack.util.executable.Executable(path)
-    else:
-        msg = "Unable to locate {0} command in {1}"
-        raise RuntimeError(msg.format(spec.name, home.bin))
+    raise RuntimeError(f"Unable to locate {spec.name} command in {home.bin}")
 
 
-def _headers_default_handler(descriptor, spec, cls):
+def _headers_default_handler(spec: "Spec"):
     """Default handler when looking for the 'headers' attribute.
 
     Tries to search for ``*.h`` files recursively starting from
     ``spec.package.home.include``.
 
     Parameters:
-        descriptor (ForwardQueryToPackage): descriptor that triggered the call
-        spec (Spec): spec that is being queried
-        cls (type(spec)): type of spec, to match the signature of the
-            descriptor ``__get__`` method
+        spec: spec that is being queried
 
     Returns:
         HeaderList: The headers in ``prefix.include``
@@ -1080,12 +1072,10 @@ def _headers_default_handler(descriptor, spec, cls):
 
     if headers:
         return headers
-    else:
-        msg = "Unable to locate {0} headers in {1}"
-        raise spack.error.NoHeadersError(msg.format(spec.name, home))
+    raise spack.error.NoHeadersError(f"Unable to locate {spec.name} headers in {home}")
 
 
-def _libs_default_handler(descriptor, spec, cls):
+def _libs_default_handler(spec: "Spec"):
     """Default handler when looking for the 'libs' attribute.
 
     Tries to search for ``lib{spec.name}`` recursively starting from
@@ -1093,10 +1083,7 @@ def _libs_default_handler(descriptor, spec, cls):
     ``{spec.name}`` instead.
 
     Parameters:
-        descriptor (ForwardQueryToPackage): descriptor that triggered the call
-        spec (Spec): spec that is being queried
-        cls (type(spec)): type of spec, to match the signature of the
-            descriptor ``__get__`` method
+        spec: spec that is being queried
 
     Returns:
         LibraryList: The libraries found
@@ -1135,27 +1122,33 @@ def _libs_default_handler(descriptor, spec, cls):
         if libs:
             return libs
 
-    msg = "Unable to recursively locate {0} libraries in {1}"
-    raise spack.error.NoLibrariesError(msg.format(spec.name, home))
+    raise spack.error.NoLibrariesError(
+        f"Unable to recursively locate {spec.name} libraries in {home}"
+    )
 
 
 class ForwardQueryToPackage:
     """Descriptor used to forward queries from Spec to Package"""
 
-    def __init__(self, attribute_name, default_handler=None):
+    def __init__(
+        self,
+        attribute_name: str,
+        default_handler: Optional[Callable[["Spec"], Any]] = None,
+        _indirect: bool = False,
+    ) -> None:
         """Create a new descriptor.
 
         Parameters:
-            attribute_name (str): name of the attribute to be
-                searched for in the Package instance
-            default_handler (callable, optional): default function to be
-                called if the attribute was not found in the Package
-                instance
+            attribute_name: name of the attribute to be searched for in the Package instance
+            default_handler: default function to be called if the attribute was not found in the
+                Package instance
+            _indirect: temporarily added to redirect a query to another package.
         """
         self.attribute_name = attribute_name
         self.default = default_handler
+        self.indirect = _indirect
 
-    def __get__(self, instance, cls):
+    def __get__(self, instance: "SpecBuildInterface", cls):
         """Retrieves the property from Package using a well defined chain
         of responsibility.
 
@@ -1177,13 +1170,18 @@ def __get__(self, instance, cls):
         indicating a query failure, e.g. that library files were not found in a
         'libs' query.
         """
-        pkg = instance.package
+        # TODO: this indirection exist solely for `spec["python"].command` to actually return
+        # spec["python-venv"].command. It should be removed when `python` is a virtual.
+        if self.indirect and instance.indirect_spec:
+            pkg = instance.indirect_spec.package
+        else:
+            pkg = instance.wrapped_obj.package
         try:
             query = instance.last_query
         except AttributeError:
             # There has been no query yet: this means
             # a spec is trying to access its own attributes
-            _ = instance[instance.name]  # NOQA: ignore=F841
+            _ = instance.wrapped_obj[instance.wrapped_obj.name]  # NOQA: ignore=F841
             query = instance.last_query
 
         callbacks_chain = []
@@ -1195,7 +1193,8 @@ def __get__(self, instance, cls):
         callbacks_chain.append(lambda: getattr(pkg, self.attribute_name))
         # Final resort : default callback
         if self.default is not None:
-            callbacks_chain.append(lambda: self.default(self, instance, cls))
+            _default = self.default  # make mypy happy
+            callbacks_chain.append(lambda: _default(instance.wrapped_obj))
 
         # Trigger the callbacks in order, the first one producing a
         # value wins
@@ -1254,25 +1253,33 @@ def __set__(self, instance, value):
 class SpecBuildInterface(lang.ObjectWrapper):
     # home is available in the base Package so no default is needed
     home = ForwardQueryToPackage("home", default_handler=None)
-
-    command = ForwardQueryToPackage("command", default_handler=_command_default_handler)
-
     headers = ForwardQueryToPackage("headers", default_handler=_headers_default_handler)
-
     libs = ForwardQueryToPackage("libs", default_handler=_libs_default_handler)
+    command = ForwardQueryToPackage(
+        "command", default_handler=_command_default_handler, _indirect=True
+    )
 
-    def __init__(self, spec, name, query_parameters):
+    def __init__(self, spec: "Spec", name: str, query_parameters: List[str], _parent: "Spec"):
         super().__init__(spec)
         # Adding new attributes goes after super() call since the ObjectWrapper
         # resets __dict__ to behave like the passed object
         original_spec = getattr(spec, "wrapped_obj", spec)
         self.wrapped_obj = original_spec
-        self.token = original_spec, name, query_parameters
+        self.token = original_spec, name, query_parameters, _parent
         is_virtual = spack.repo.PATH.is_virtual(name)
         self.last_query = QueryState(
             name=name, extra_parameters=query_parameters, isvirtual=is_virtual
         )
 
+        # TODO: this ad-hoc logic makes `spec["python"].command` return
+        # `spec["python-venv"].command` and should be removed when `python` is a virtual.
+        self.indirect_spec = None
+        if spec.name == "python":
+            python_venvs = _parent.dependencies("python-venv")
+            if not python_venvs:
+                return
+            self.indirect_spec = python_venvs[0]
+
     def __reduce__(self):
         return SpecBuildInterface, self.token
 
@@ -3898,9 +3905,13 @@ def satisfies(self, other: Union[str, "Spec"], deps: bool = True) -> bool:
         if not self._dependencies:
             return False
 
-        # If we arrived here, then rhs is abstract. At the moment we don't care about the edge
-        # structure of an abstract DAG, so we check if any edge could satisfy the properties
-        # we ask for.
+        # If we arrived here, the lhs root node satisfies the rhs root node. Now we need to check
+        # all the edges that have an abstract parent, and verify that they match some edge in the
+        # lhs.
+        #
+        # It might happen that the rhs brings in concrete sub-DAGs. For those we don't need to
+        # verify the edge properties, cause everything is encoded in the hash of the nodes that
+        # will be verified later.
         lhs_edges: Dict[str, Set[DependencySpec]] = collections.defaultdict(set)
         for rhs_edge in other.traverse_edges(root=False, cover="edges"):
             # If we are checking for ^mpi we need to verify if there is any edge
@@ -3910,6 +3921,10 @@ def satisfies(self, other: Union[str, "Spec"], deps: bool = True) -> bool:
             if not rhs_edge.virtuals:
                 continue
 
+            # Skip edges from a concrete sub-DAG
+            if rhs_edge.parent.concrete:
+                continue
+
             if not lhs_edges:
                 # Construct a map of the link/run subDAG + direct "build" edges,
                 # keyed by dependency name
@@ -4129,7 +4144,7 @@ def version(self):
             raise spack.error.SpecError("Spec version is not concrete: " + str(self))
         return self.versions[0]
 
-    def __getitem__(self, name):
+    def __getitem__(self, name: str):
         """Get a dependency from the spec by its name. This call implicitly
         sets a query state in the package being retrieved. The behavior of
         packages may be influenced by additional query parameters that are
@@ -4138,7 +4153,7 @@ def __getitem__(self, name):
         Note that if a virtual package is queried a copy of the Spec is
         returned while for non-virtual a reference is returned.
         """
-        query_parameters = name.split(":")
+        query_parameters: List[str] = name.split(":")
         if len(query_parameters) > 2:
             raise KeyError("key has more than one ':' symbol. At most one is admitted.")
 
@@ -4161,7 +4176,7 @@ def __getitem__(self, name):
         )
 
         try:
-            value = next(
+            child: Spec = next(
                 itertools.chain(
                     # Regular specs
                     (x for x in order() if x.name == name),
@@ -4178,9 +4193,9 @@ def __getitem__(self, name):
             raise KeyError(f"No spec with name {name} in {self}")
 
         if self._concrete:
-            return SpecBuildInterface(value, name, query_parameters)
+            return SpecBuildInterface(child, name, query_parameters, _parent=self)
 
-        return value
+        return child
 
     def __contains__(self, spec):
         """True if this spec or some dependency satisfies the spec.

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):

lib/spack/spack/test/bindist.py

@@ -22,6 +22,7 @@
 import archspec.cpu
 
 from llnl.util.filesystem import join_path, visit_directory_tree
+from llnl.util.symlink import readlink
 
 import spack.binary_distribution as bindist
 import spack.caches
@@ -1062,10 +1063,10 @@ def test_tarball_common_prefix(dummy_prefix, tmpdir):
         assert set(os.listdir(os.path.join("prefix2", "share"))) == {"file"}
 
         # Relative symlink should still be correct
-        assert os.readlink(os.path.join("prefix2", "bin", "relative_app_link")) == "app"
+        assert readlink(os.path.join("prefix2", "bin", "relative_app_link")) == "app"
 
         # Absolute symlink should remain absolute -- this is for relocation to fix up.
-        assert os.readlink(os.path.join("prefix2", "bin", "absolute_app_link")) == os.path.join(
+        assert readlink(os.path.join("prefix2", "bin", "absolute_app_link")) == os.path.join(
             dummy_prefix, "bin", "app"
         )
 

lib/spack/spack/test/build_environment.py

@@ -14,6 +14,7 @@
 
 import spack.build_environment
 import spack.config
+import spack.deptypes as dt
 import spack.package_base
 import spack.spec
 import spack.util.spack_yaml as syaml
@@ -716,3 +717,21 @@ def test_build_system_globals_only_set_on_root_during_build(default_mock_concret
     for depth, spec in root.traverse(depth=True, root=True):
         for variable in build_variables:
             assert hasattr(spec.package.module, variable) == should_be_set(depth)
+
+
+def test_rpath_with_duplicate_link_deps():
+    """If we have two instances of one package in the same link sub-dag, only the newest version is
+    rpath'ed. This is for runtime support without splicing."""
+    runtime_1 = spack.spec.Spec("runtime@=1.0")
+    runtime_2 = spack.spec.Spec("runtime@=2.0")
+    child = spack.spec.Spec("child@=1.0")
+    root = spack.spec.Spec("root@=1.0")
+
+    root.add_dependency_edge(child, depflag=dt.LINK, virtuals=())
+    root.add_dependency_edge(runtime_2, depflag=dt.LINK, virtuals=())
+    child.add_dependency_edge(runtime_1, depflag=dt.LINK, virtuals=())
+
+    rpath_deps = spack.build_environment._get_rpath_deps_from_spec(root, transitive_rpaths=True)
+    assert child in rpath_deps
+    assert runtime_2 in rpath_deps
+    assert runtime_1 not in rpath_deps

lib/spack/spack/test/ci.py

@@ -51,7 +51,7 @@ def __init__(self, response_code=200, content_to_read=[]):
         self._content = content_to_read
         self._read = [False for c in content_to_read]
 
-    def open(self, request):
+    def open(self, request, data=None, timeout=object()):
         return self
 
     def getcode(self):

lib/spack/spack/test/cmd/ci.py

@@ -760,7 +760,6 @@ def test_ci_rebuild_mock_success(
     rebuild_env = create_rebuild_env(tmpdir, pkg_name, broken_tests)
 
     monkeypatch.setattr(spack.cmd.ci, "SPACK_COMMAND", "echo")
-    monkeypatch.setattr(spack.cmd.ci, "MAKE_COMMAND", "echo")
 
     with rebuild_env.env_dir.as_cwd():
         activate_rebuild_env(tmpdir, pkg_name, rebuild_env)
@@ -843,7 +842,6 @@ def test_ci_rebuild(
         ci_cmd("rebuild", "--tests", fail_on_error=False)
 
     monkeypatch.setattr(spack.cmd.ci, "SPACK_COMMAND", "notcommand")
-    monkeypatch.setattr(spack.cmd.ci, "MAKE_COMMAND", "notcommand")
     monkeypatch.setattr(spack.cmd.ci, "INSTALL_FAIL_CODE", 127)
 
     with rebuild_env.env_dir.as_cwd():

lib/spack/spack/test/cmd/common/arguments.py

@@ -123,7 +123,13 @@ def test_root_and_dep_match_returns_root(mock_packages, mutable_mock_env_path):
 
 
 @pytest.mark.parametrize(
-    "arg,conf", [("--reuse", True), ("--fresh", False), ("--reuse-deps", "dependencies")]
+    "arg,conf",
+    [
+        ("--reuse", True),
+        ("--fresh", False),
+        ("--reuse-deps", "dependencies"),
+        ("--fresh-roots", "dependencies"),
+    ],
 )
 def test_concretizer_arguments(mutable_config, mock_packages, arg, conf):
     """Ensure that ConfigSetAction is doing the right thing."""

lib/spack/spack/test/cmd/compiler.py

@@ -261,15 +261,14 @@ def test_compiler_list_empty(no_compilers_yaml, working_env, compilers_dir):
     [
         (
             {
-                "spec": "gcc@=7.7.7 os=foobar target=x86_64",
+                "spec": "gcc@=7.7.7 languages=c,cxx,fortran os=foobar target=x86_64",
                 "prefix": "/path/to/fake",
                 "modules": ["gcc/7.7.7", "foobar"],
                 "extra_attributes": {
-                    "paths": {
-                        "cc": "/path/to/fake/gcc",
+                    "compilers": {
+                        "c": "/path/to/fake/gcc",
                         "cxx": "/path/to/fake/g++",
-                        "fc": "/path/to/fake/gfortran",
-                        "f77": "/path/to/fake/gfortran",
+                        "fortran": "/path/to/fake/gfortran",
                     },
                     "flags": {"fflags": "-ffree-form"},
                 },
@@ -285,26 +284,7 @@ def test_compiler_list_empty(no_compilers_yaml, working_env, compilers_dir):
 \tmodules  = ['gcc/7.7.7', 'foobar']
 \toperating system  = foobar
 """,
-        ),
-        (
-            {
-                "spec": "gcc@7.7.7",
-                "prefix": "{prefix}",
-                "modules": ["gcc/7.7.7", "foobar"],
-                "extra_attributes": {"flags": {"fflags": "-ffree-form"}},
-            },
-            """gcc@7.7.7:
-\tpaths:
-\t\tcc = {compilers_dir}{sep}gcc-8{suffix}
-\t\tcxx = {compilers_dir}{sep}g++-8{suffix}
-\t\tf77 = {compilers_dir}{sep}gfortran-8{suffix}
-\t\tfc = {compilers_dir}{sep}gfortran-8{suffix}
-\tflags:
-\t\tfflags = ['-ffree-form']
-\tmodules  = ['gcc/7.7.7', 'foobar']
-\toperating system  = debian6
-""",
-        ),
+        )
     ],
 )
 def test_compilers_shows_packages_yaml(

lib/spack/spack/test/cmd/env.py

@@ -15,6 +15,7 @@
 import llnl.util.filesystem as fs
 import llnl.util.link_tree
 import llnl.util.tty as tty
+from llnl.util.symlink import readlink
 
 import spack.cmd.env
 import spack.config
@@ -60,6 +61,27 @@
 sep = os.sep
 
 
+def setup_combined_multiple_env():
+    env("create", "test1")
+    test1 = ev.read("test1")
+    with test1:
+        add("zlib")
+    test1.concretize()
+    test1.write()
+
+    env("create", "test2")
+    test2 = ev.read("test2")
+    with test2:
+        add("libelf")
+    test2.concretize()
+    test2.write()
+
+    env("create", "--include-concrete", "test1", "--include-concrete", "test2", "combined_env")
+    combined = ev.read("combined_env")
+
+    return test1, test2, combined
+
+
 @pytest.fixture()
 def environment_from_manifest(tmp_path):
     """Returns a new environment named 'test' from the content of a manifest file."""
@@ -369,6 +391,29 @@ def test_env_install_single_spec(install_mockery, mock_fetch):
     assert e.specs_by_hash[e.concretized_order[0]].name == "cmake-client"
 
 
+@pytest.mark.parametrize("unify", [True, False, "when_possible"])
+def test_env_install_include_concrete_env(unify, install_mockery, mock_fetch):
+    test1, test2, combined = setup_combined_multiple_env()
+
+    combined.concretize()
+    combined.write()
+
+    combined.unify = unify
+
+    with combined:
+        install()
+
+    test1_roots = test1.concretized_order
+    test2_roots = test2.concretized_order
+    combined_included_roots = combined.included_concretized_order
+
+    for spec in combined.all_specs():
+        assert spec.installed
+
+    assert test1_roots == combined_included_roots[test1.path]
+    assert test2_roots == combined_included_roots[test2.path]
+
+
 def test_env_roots_marked_explicit(install_mockery, mock_fetch):
     install = SpackCommand("install")
     install("dependent-install")
@@ -557,6 +602,41 @@ def test_remove_command():
         assert "mpileaks@" not in find("--show-concretized")
 
 
+def test_bad_remove_included_env():
+    env("create", "test")
+    test = ev.read("test")
+
+    with test:
+        add("mpileaks")
+
+    test.concretize()
+    test.write()
+
+    env("create", "--include-concrete", "test", "combined_env")
+
+    with pytest.raises(SpackCommandError):
+        env("remove", "test")
+
+
+def test_force_remove_included_env():
+    env("create", "test")
+    test = ev.read("test")
+
+    with test:
+        add("mpileaks")
+
+    test.concretize()
+    test.write()
+
+    env("create", "--include-concrete", "test", "combined_env")
+
+    rm_output = env("remove", "-f", "-y", "test")
+    list_output = env("list")
+
+    assert '"test" is being used by environment "combined_env"' in rm_output
+    assert "test" not in list_output
+
+
 def test_environment_status(capsys, tmpdir):
     with tmpdir.as_cwd():
         with capsys.disabled():
@@ -1636,6 +1716,275 @@ def test_env_without_view_install(tmpdir, mock_stage, mock_fetch, install_mocker
     check_mpileaks_and_deps_in_view(view_dir)
 
 
+@pytest.mark.parametrize("env_name", [True, False])
+def test_env_include_concrete_env_yaml(env_name):
+    env("create", "test")
+    test = ev.read("test")
+
+    with test:
+        add("mpileaks")
+    test.concretize()
+    test.write()
+
+    environ = "test" if env_name else test.path
+
+    env("create", "--include-concrete", environ, "combined_env")
+
+    combined = ev.read("combined_env")
+    combined_yaml = combined.manifest["spack"]
+
+    assert "include_concrete" in combined_yaml
+    assert test.path in combined_yaml["include_concrete"]
+
+
+def test_env_bad_include_concrete_env():
+    with pytest.raises(ev.SpackEnvironmentError):
+        env("create", "--include-concrete", "nonexistant_env", "combined_env")
+
+
+def test_env_not_concrete_include_concrete_env():
+    env("create", "test")
+    test = ev.read("test")
+
+    with test:
+        add("mpileaks")
+
+    with pytest.raises(ev.SpackEnvironmentError):
+        env("create", "--include-concrete", "test", "combined_env")
+
+
+def test_env_multiple_include_concrete_envs():
+    test1, test2, combined = setup_combined_multiple_env()
+
+    combined_yaml = combined.manifest["spack"]
+
+    assert test1.path in combined_yaml["include_concrete"][0]
+    assert test2.path in combined_yaml["include_concrete"][1]
+
+    # No local specs in the combined env
+    assert not combined_yaml["specs"]
+
+
+def test_env_include_concrete_envs_lockfile():
+    test1, test2, combined = setup_combined_multiple_env()
+
+    combined_yaml = combined.manifest["spack"]
+
+    assert "include_concrete" in combined_yaml
+    assert test1.path in combined_yaml["include_concrete"]
+
+    with open(combined.lock_path) as f:
+        lockfile_as_dict = combined._read_lockfile(f)
+
+    assert set(
+        entry["hash"] for entry in lockfile_as_dict["include_concrete"][test1.path]["roots"]
+    ) == set(test1.specs_by_hash)
+    assert set(
+        entry["hash"] for entry in lockfile_as_dict["include_concrete"][test2.path]["roots"]
+    ) == set(test2.specs_by_hash)
+
+
+def test_env_include_concrete_add_env():
+    test1, test2, combined = setup_combined_multiple_env()
+
+    # crete new env & crecretize
+    env("create", "new")
+    new_env = ev.read("new")
+    with new_env:
+        add("mpileaks")
+
+    new_env.concretize()
+    new_env.write()
+
+    # add new env to combined
+    combined.included_concrete_envs.append(new_env.path)
+
+    # assert thing haven't changed yet
+    with open(combined.lock_path) as f:
+        lockfile_as_dict = combined._read_lockfile(f)
+
+    assert new_env.path not in lockfile_as_dict["include_concrete"].keys()
+
+    # concretize combined env with new env
+    combined.concretize()
+    combined.write()
+
+    # assert changes
+    with open(combined.lock_path) as f:
+        lockfile_as_dict = combined._read_lockfile(f)
+
+    assert new_env.path in lockfile_as_dict["include_concrete"].keys()
+
+
+def test_env_include_concrete_remove_env():
+    test1, test2, combined = setup_combined_multiple_env()
+
+    # remove test2 from combined
+    combined.included_concrete_envs = [test1.path]
+
+    # assert test2 is still in combined's lockfile
+    with open(combined.lock_path) as f:
+        lockfile_as_dict = combined._read_lockfile(f)
+
+    assert test2.path in lockfile_as_dict["include_concrete"].keys()
+
+    # reconcretize combined
+    combined.concretize()
+    combined.write()
+
+    # assert test2 is not in combined's lockfile
+    with open(combined.lock_path) as f:
+        lockfile_as_dict = combined._read_lockfile(f)
+
+    assert test2.path not in lockfile_as_dict["include_concrete"].keys()
+
+
+@pytest.mark.parametrize("unify", [True, False, "when_possible"])
+def test_env_include_concrete_env_reconcretized(unify):
+    """Double check to make sure that concrete_specs for the local specs is empty
+    after recocnretizing.
+    """
+    _, _, combined = setup_combined_multiple_env()
+
+    combined.unify = unify
+
+    with open(combined.lock_path) as f:
+        lockfile_as_dict = combined._read_lockfile(f)
+
+    assert not lockfile_as_dict["roots"]
+    assert not lockfile_as_dict["concrete_specs"]
+
+    combined.concretize()
+    combined.write()
+
+    with open(combined.lock_path) as f:
+        lockfile_as_dict = combined._read_lockfile(f)
+
+    assert not lockfile_as_dict["roots"]
+    assert not lockfile_as_dict["concrete_specs"]
+
+
+def test_concretize_include_concrete_env():
+    test1, _, combined = setup_combined_multiple_env()
+
+    with test1:
+        add("mpileaks")
+    test1.concretize()
+    test1.write()
+
+    assert Spec("mpileaks") in test1.concretized_user_specs
+    assert Spec("mpileaks") not in combined.included_concretized_user_specs[test1.path]
+
+    combined.concretize()
+    combined.write()
+
+    assert Spec("mpileaks") in combined.included_concretized_user_specs[test1.path]
+
+
+def test_concretize_nested_include_concrete_envs():
+    env("create", "test1")
+    test1 = ev.read("test1")
+    with test1:
+        add("zlib")
+    test1.concretize()
+    test1.write()
+
+    env("create", "--include-concrete", "test1", "test2")
+    test2 = ev.read("test2")
+    with test2:
+        add("libelf")
+    test2.concretize()
+    test2.write()
+
+    env("create", "--include-concrete", "test2", "test3")
+    test3 = ev.read("test3")
+
+    with open(test3.lock_path) as f:
+        lockfile_as_dict = test3._read_lockfile(f)
+
+    assert test2.path in lockfile_as_dict["include_concrete"]
+    assert test1.path in lockfile_as_dict["include_concrete"][test2.path]["include_concrete"]
+
+    assert Spec("zlib") in test3.included_concretized_user_specs[test1.path]
+
+
+def test_concretize_nested_included_concrete():
+    """Confirm that nested included environments use specs concretized at
+    environment creation time and change with reconcretization."""
+    env("create", "test1")
+    test1 = ev.read("test1")
+    with test1:
+        add("zlib")
+    test1.concretize()
+    test1.write()
+
+    # test2 should include test1 with zlib
+    env("create", "--include-concrete", "test1", "test2")
+    test2 = ev.read("test2")
+    with test2:
+        add("libelf")
+    test2.concretize()
+    test2.write()
+
+    assert Spec("zlib") in test2.included_concretized_user_specs[test1.path]
+
+    # Modify/re-concretize test1 to replace zlib with mpileaks
+    with test1:
+        remove("zlib")
+        add("mpileaks")
+    test1.concretize()
+    test1.write()
+
+    # test3 should include the latest concretization of test1
+    env("create", "--include-concrete", "test1", "test3")
+    test3 = ev.read("test3")
+    with test3:
+        add("callpath")
+    test3.concretize()
+    test3.write()
+
+    included_specs = test3.included_concretized_user_specs[test1.path]
+    assert len(included_specs) == 1
+    assert Spec("mpileaks") in included_specs
+
+    # The last concretization of test4's included environments should have test2
+    # with the original concretized test1 spec and test3 with the re-concretized
+    # test1 spec.
+    env("create", "--include-concrete", "test2", "--include-concrete", "test3", "test4")
+    test4 = ev.read("test4")
+
+    def included_included_spec(path1, path2):
+        included_path1 = test4.included_concrete_spec_data[path1]
+        included_path2 = included_path1["include_concrete"][path2]
+        return included_path2["roots"][0]["spec"]
+
+    included_test2_test1 = included_included_spec(test2.path, test1.path)
+    assert "zlib" in included_test2_test1
+
+    included_test3_test1 = included_included_spec(test3.path, test1.path)
+    assert "mpileaks" in included_test3_test1
+
+    # test4's concretized specs should reflect the original concretization.
+    concrete_specs = [s for s, _ in test4.concretized_specs()]
+    expected = [Spec(s) for s in ["libelf", "zlib", "mpileaks", "callpath"]]
+    assert all(s in concrete_specs for s in expected)
+
+    # Re-concretize test2 to reflect the new concretization of included test1
+    # to remove zlib and write it out so it can be picked up by test4.
+    # Re-concretize test4 to reflect the re-concretization of included test2
+    # and ensure that its included specs are up-to-date
+    test2.concretize()
+    test2.write()
+    test4.concretize()
+
+    concrete_specs = [s for s, _ in test4.concretized_specs()]
+    assert Spec("zlib") not in concrete_specs
+
+    # Expecting mpileaks to appear only once
+    expected = [Spec(s) for s in ["libelf", "mpileaks", "callpath"]]
+    assert len(concrete_specs) == 3 and all(s in concrete_specs for s in expected)
+
+
 def test_env_config_view_default(
     environment_from_manifest, mock_stage, mock_fetch, install_mockery
 ):
@@ -3290,7 +3639,7 @@ def test_create_and_activate_managed(tmp_path):
 def test_create_and_activate_anonymous(tmp_path):
     with fs.working_dir(str(tmp_path)):
         env_dir = os.path.join(str(tmp_path), "foo")
-        shell = env("activate", "--without-view", "--create", "--sh", "-d", env_dir)
+        shell = env("activate", "--without-view", "--create", "--sh", env_dir)
         active_env_var = next(line for line in shell.splitlines() if ev.spack_env_var in line)
         assert str(env_dir) in active_env_var
         assert ev.is_env_dir(env_dir)
@@ -4066,8 +4415,8 @@ def test_env_view_resolves_identical_file_conflicts(tmp_path, install_mockery, m
     #   view-file/bin/
     #     x                                          # expect this x to be linked
 
-    assert os.readlink(tmp_path / "view" / "bin" / "x") == bottom.bin.x
-    assert os.readlink(tmp_path / "view" / "bin" / "y") == top.bin.y
+    assert readlink(tmp_path / "view" / "bin" / "x") == bottom.bin.x
+    assert readlink(tmp_path / "view" / "bin" / "y") == top.bin.y
 
 
 def test_env_view_ignores_different_file_conflicts(tmp_path, install_mockery, mock_fetch):
@@ -4078,4 +4427,4 @@ def test_env_view_ignores_different_file_conflicts(tmp_path, install_mockery, mo
         install()
         prefix_dependent = e.matching_spec("view-ignore-conflict").prefix
     # The dependent's file is linked into the view
-    assert os.readlink(tmp_path / "view" / "bin" / "x") == prefix_dependent.bin.x
+    assert readlink(tmp_path / "view" / "bin" / "x") == prefix_dependent.bin.x

lib/spack/spack/test/cmd/extensions.py

@@ -33,21 +33,23 @@ def check_output(ni):
             packages = extensions("-s", "packages", "python")
             installed = extensions("-s", "installed", "python")
         assert "==> python@2.7.11" in output
-        assert "==> 2 extensions" in output
+        assert "==> 3 extensions" in output
         assert "py-extension1" in output
         assert "py-extension2" in output
+        assert "python-venv" in output
 
-        assert "==> 2 extensions" in packages
+        assert "==> 3 extensions" in packages
         assert "py-extension1" in packages
         assert "py-extension2" in packages
+        assert "python-venv" in packages
         assert "installed" not in packages
 
-        assert ("%s installed" % (ni if ni else "None")) in output
-        assert ("%s installed" % (ni if ni else "None")) in installed
+        assert f"{ni if ni else 'None'} installed" in output
+        assert f"{ni if ni else 'None'} installed" in installed
 
-    check_output(2)
+    check_output(3)
     ext2.package.do_uninstall(force=True)
-    check_output(1)
+    check_output(2)
 
 
 def test_extensions_no_arguments(mock_packages):

lib/spack/spack/test/cmd/find.py

@@ -349,6 +349,87 @@ def test_find_prefix_in_env(
         # Would throw error on regression
 
 
+def test_find_specs_include_concrete_env(mutable_mock_env_path, config, mutable_mock_repo, tmpdir):
+    path = tmpdir.join("spack.yaml")
+
+    with tmpdir.as_cwd():
+        with open(str(path), "w") as f:
+            f.write(
+                """\
+spack:
+  specs:
+  - mpileaks
+"""
+            )
+        env("create", "test1", "spack.yaml")
+
+    test1 = ev.read("test1")
+    test1.concretize()
+    test1.write()
+
+    with tmpdir.as_cwd():
+        with open(str(path), "w") as f:
+            f.write(
+                """\
+spack:
+  specs:
+  - libelf
+"""
+            )
+        env("create", "test2", "spack.yaml")
+
+    test2 = ev.read("test2")
+    test2.concretize()
+    test2.write()
+
+    env("create", "--include-concrete", "test1", "--include-concrete", "test2", "combined_env")
+
+    with ev.read("combined_env"):
+        output = find()
+
+    assert "No root specs" in output
+    assert "Included specs" in output
+    assert "mpileaks" in output
+    assert "libelf" in output
+
+
+def test_find_specs_nested_include_concrete_env(
+    mutable_mock_env_path, config, mutable_mock_repo, tmpdir
+):
+    path = tmpdir.join("spack.yaml")
+
+    with tmpdir.as_cwd():
+        with open(str(path), "w") as f:
+            f.write(
+                """\
+spack:
+  specs:
+  - mpileaks
+"""
+            )
+        env("create", "test1", "spack.yaml")
+
+    test1 = ev.read("test1")
+    test1.concretize()
+    test1.write()
+
+    env("create", "--include-concrete", "test1", "test2")
+    test2 = ev.read("test2")
+    test2.add("libelf")
+    test2.concretize()
+    test2.write()
+
+    env("create", "--include-concrete", "test2", "test3")
+
+    with ev.read("test3"):
+        output = find()
+
+    assert "No root specs" in output
+    assert "Included specs" in output
+    assert "mpileaks" in output
+    assert "libelf" in output
+
+
 def test_find_loaded(database, working_env):
     output = find("--loaded", "--group")
     assert output == ""

lib/spack/spack/test/compilers/basics.py

@@ -943,3 +943,17 @@ def test_detection_requires_c_compiler(detected_versions, expected_length):
     """
     result = spack.compilers.make_compiler_list(detected_versions)
     assert len(result) == expected_length
+
+
+def test_compiler_environment(working_env):
+    """Test whether environment modifications from compilers are applied in compiler_environment"""
+    os.environ.pop("TEST", None)
+    compiler = Compiler(
+        "gcc@=13.2.0",
+        operating_system="ubuntu20.04",
+        target="x86_64",
+        paths=["/test/bin/gcc", "/test/bin/g++"],
+        environment={"set": {"TEST": "yes"}},
+    )
+    with compiler.compiler_environment():
+        assert os.environ["TEST"] == "yes"

lib/spack/spack/test/concretize.py

@@ -1244,10 +1244,11 @@ def test_variant_not_default(self):
 
     @pytest.mark.regression("20055")
     @pytest.mark.only_clingo("Use case not supported by the original concretizer")
-    def test_custom_compiler_version(self, mutable_config, compiler_factory):
+    def test_custom_compiler_version(self, mutable_config, compiler_factory, monkeypatch):
         mutable_config.set(
             "compilers", [compiler_factory(spec="gcc@10foo", operating_system="redhat6")]
         )
+        monkeypatch.setattr(spack.compiler.Compiler, "real_version", "10.2.1")
         s = Spec("a %gcc@10foo os=redhat6").concretized()
         assert "%gcc@10foo" in s
 
@@ -1766,21 +1767,21 @@ def test_reuse_with_unknown_package_dont_raise(self, tmpdir, temporary_store, mo
             assert s.namespace == "builtin.mock"
 
     @pytest.mark.parametrize(
-        "specs,expected",
+        "specs,expected,libc_offset",
         [
-            (["libelf", "libelf@0.8.10"], 1),
-            (["libdwarf%gcc", "libelf%clang"], 2),
-            (["libdwarf%gcc", "libdwarf%clang"], 3),
-            (["libdwarf^libelf@0.8.12", "libdwarf^libelf@0.8.13"], 4),
-            (["hdf5", "zmpi"], 3),
-            (["hdf5", "mpich"], 2),
-            (["hdf5^zmpi", "mpich"], 4),
-            (["mpi", "zmpi"], 2),
-            (["mpi", "mpich"], 1),
+            (["libelf", "libelf@0.8.10"], 1, 1),
+            (["libdwarf%gcc", "libelf%clang"], 2, 1),
+            (["libdwarf%gcc", "libdwarf%clang"], 3, 2),
+            (["libdwarf^libelf@0.8.12", "libdwarf^libelf@0.8.13"], 4, 1),
+            (["hdf5", "zmpi"], 3, 1),
+            (["hdf5", "mpich"], 2, 1),
+            (["hdf5^zmpi", "mpich"], 4, 1),
+            (["mpi", "zmpi"], 2, 1),
+            (["mpi", "mpich"], 1, 1),
         ],
     )
     @pytest.mark.only_clingo("Original concretizer cannot concretize in rounds")
-    def test_best_effort_coconcretize(self, specs, expected):
+    def test_best_effort_coconcretize(self, specs, expected, libc_offset):
         specs = [Spec(s) for s in specs]
         solver = spack.solver.asp.Solver()
         solver.reuse = False
@@ -1789,7 +1790,9 @@ def test_best_effort_coconcretize(self, specs, expected):
             for s in result.specs:
                 concrete_specs.update(s.traverse())
 
-        libc_offset = 1 if spack.solver.asp.using_libc_compatibility() else 0
+        if not spack.solver.asp.using_libc_compatibility():
+            libc_offset = 0
+
         assert len(concrete_specs) == expected + libc_offset
 
     @pytest.mark.parametrize(
@@ -1913,11 +1916,11 @@ def test_version_weight_and_provenance(self):
             libc_offset = 1 if spack.solver.asp.using_libc_compatibility() else 0
             criteria = [
                 (num_specs - 1 - libc_offset, None, "number of packages to build (vs. reuse)"),
-                (2, 0, "version badness"),
+                (2, 0, "version badness (non roots)"),
             ]
 
             for criterion in criteria:
-                assert criterion in result.criteria, result_spec
+                assert criterion in result.criteria, criterion
             assert result_spec.satisfies("^b@1.0")
 
     @pytest.mark.only_clingo("Use case not supported by the original concretizer")
@@ -2448,6 +2451,127 @@ def _default_libc(self):
         s = Spec("a %gcc@=13.2.0").concretized()
         assert s.satisfies("%gcc@13.2.0")
 
+    @pytest.mark.regression("43267")
+    def test_spec_with_build_dep_from_json(self, tmp_path):
+        """Tests that we can correctly concretize a spec, when we express its dependency as a
+        concrete spec to be read from JSON.
+
+        The bug was triggered by missing virtuals on edges that were trimmed from pure build
+        dependencies.
+        """
+        build_dep = Spec("dttop").concretized()
+        json_file = tmp_path / "build.json"
+        json_file.write_text(build_dep.to_json())
+        s = Spec(f"dtuse ^{str(json_file)}").concretized()
+        assert s["dttop"].dag_hash() == build_dep.dag_hash()
+
+    @pytest.mark.regression("44040")
+    @pytest.mark.only_clingo("Use case not supported by the original concretizer")
+    def test_exclude_specs_from_reuse(self, monkeypatch):
+        """Tests that we can exclude a spec from reuse when concretizing, and that the spec
+        is not added back to the solve as a dependency of another reusable spec.
+
+        The expected spec is:
+
+        o callpath@1.0
+        |\
+        | |\
+        o | | mpich@3.0.4
+        |/ /
+        | o dyninst@8.2
+        |/|
+        | |\
+        | | o libdwarf@20130729
+        | |/|
+        |/|/
+        | o libelf@0.8.13
+        |/
+        o glibc@2.31
+        """
+        # Prepare a mock mirror that returns an old version of dyninst
+        request_str = "callpath ^mpich"
+        reused = Spec(f"{request_str} ^dyninst@8.1.1").concretized()
+        monkeypatch.setattr(spack.solver.asp, "_specs_from_mirror", lambda: [reused])
+
+        # Exclude dyninst from reuse, so we expect that the old version is not taken into account
+        with spack.config.override(
+            "concretizer:reuse", {"from": [{"type": "buildcache", "exclude": ["dyninst"]}]}
+        ):
+            result = Spec(request_str).concretized()
+
+        assert result.dag_hash() != reused.dag_hash()
+        assert result["mpich"].dag_hash() == reused["mpich"].dag_hash()
+        assert result["dyninst"].dag_hash() != reused["dyninst"].dag_hash()
+        assert result["dyninst"].satisfies("@=8.2")
+        for dep in result["dyninst"].traverse(root=False):
+            assert dep.dag_hash() == reused[dep.name].dag_hash()
+
+    @pytest.mark.regression("44091")
+    @pytest.mark.parametrize(
+        "included_externals",
+        [
+            ["deprecated-versions"],
+            # Try the empty list, to ensure that in that case everything will be included
+            # since filtering should happen only when the list is non-empty
+            [],
+        ],
+    )
+    @pytest.mark.only_clingo("Use case not supported by the original concretizer")
+    def test_include_specs_from_externals_and_libcs(
+        self, included_externals, mutable_config, tmp_path
+    ):
+        """Tests that when we include specs from externals, we always include libcs."""
+        mutable_config.set(
+            "packages",
+            {
+                "deprecated-versions": {
+                    "externals": [{"spec": "deprecated-versions@1.1.0", "prefix": str(tmp_path)}]
+                }
+            },
+        )
+        request_str = "deprecated-client"
+
+        # When using the external the version is selected even if deprecated
+        with spack.config.override(
+            "concretizer:reuse", {"from": [{"type": "external", "include": included_externals}]}
+        ):
+            result = Spec(request_str).concretized()
+
+        assert result["deprecated-versions"].satisfies("@1.1.0")
+
+        # When excluding it, we pick the non-deprecated version
+        with spack.config.override(
+            "concretizer:reuse",
+            {"from": [{"type": "external", "exclude": ["deprecated-versions"]}]},
+        ):
+            result = Spec(request_str).concretized()
+
+        assert result["deprecated-versions"].satisfies("@1.0.0")
+
+    @pytest.mark.regression("44085")
+    @pytest.mark.only_clingo("Use case not supported by the original concretizer")
+    def test_can_reuse_concrete_externals_for_dependents(self, mutable_config, tmp_path):
+        """Test that external specs that are in the DB can be reused. This means they are
+        preferred to concretizing another external from packages.yaml
+        """
+        packages_yaml = {
+            "externaltool": {"externals": [{"spec": "externaltool@2.0", "prefix": "/fake/path"}]}
+        }
+        mutable_config.set("packages", packages_yaml)
+        # Concretize with gcc@9 to get a suboptimal spec, since we have gcc@10 available
+        external_spec = Spec("externaltool@2 %gcc@9").concretized()
+        assert external_spec.external
+
+        root_specs = [Spec("sombrero")]
+        with spack.config.override("concretizer:reuse", True):
+            solver = spack.solver.asp.Solver()
+            setup = spack.solver.asp.SpackSolverSetup()
+            result, _, _ = solver.driver.solve(setup, root_specs, reuse=[external_spec])
+
+        assert len(result.specs) == 1
+        sombrero = result.specs[0]
+        assert sombrero["externaltool"].dag_hash() == external_spec.dag_hash()
+
 
 @pytest.fixture()
 def duplicates_test_repository():
@@ -2823,3 +2947,78 @@ def test_concretization_version_order():
         Version("develop"),  # likely development version
         Version("2.0"),  # deprecated
     ]
+
+
+@pytest.mark.only_clingo("Original concretizer cannot reuse specs")
+@pytest.mark.parametrize(
+    "roots,reuse_yaml,expected,not_expected,expected_length",
+    [
+        (
+            ["mpileaks"],
+            {"roots": True, "include": ["^mpich"]},
+            ["^mpich"],
+            ["^mpich2", "^zmpi"],
+            2,
+        ),
+        (
+            ["mpileaks"],
+            {"roots": True, "include": ["externaltest"]},
+            ["externaltest"],
+            ["^mpich", "^mpich2", "^zmpi"],
+            1,
+        ),
+    ],
+)
+@pytest.mark.usefixtures("database", "mock_store")
+@pytest.mark.not_on_windows("Expected length is different on Windows")
+def test_filtering_reused_specs(
+    roots, reuse_yaml, expected, not_expected, expected_length, mutable_config, monkeypatch
+):
+    """Tests that we can select which specs are to be reused, using constraints as filters"""
+    # Assume all specs have a runtime dependency
+    monkeypatch.setattr(spack.solver.asp, "_has_runtime_dependencies", lambda x: True)
+    mutable_config.set("concretizer:reuse", reuse_yaml)
+    selector = spack.solver.asp.ReusableSpecsSelector(mutable_config)
+    specs = selector.reusable_specs(roots)
+
+    assert len(specs) == expected_length
+
+    for constraint in expected:
+        assert all(x.satisfies(constraint) for x in specs)
+
+    for constraint in not_expected:
+        assert all(not x.satisfies(constraint) for x in specs)
+
+
+@pytest.mark.usefixtures("database", "mock_store")
+@pytest.mark.parametrize(
+    "reuse_yaml,expected_length",
+    [({"from": [{"type": "local"}]}, 17), ({"from": [{"type": "buildcache"}]}, 0)],
+)
+@pytest.mark.not_on_windows("Expected length is different on Windows")
+def test_selecting_reused_sources(reuse_yaml, expected_length, mutable_config, monkeypatch):
+    """Tests that we can turn on/off sources of reusable specs"""
+    # Assume all specs have a runtime dependency
+    monkeypatch.setattr(spack.solver.asp, "_has_runtime_dependencies", lambda x: True)
+    mutable_config.set("concretizer:reuse", reuse_yaml)
+    selector = spack.solver.asp.ReusableSpecsSelector(mutable_config)
+    specs = selector.reusable_specs(["mpileaks"])
+    assert len(specs) == expected_length
+
+
+@pytest.mark.parametrize(
+    "specs,include,exclude,expected",
+    [
+        # "foo" discarded by include rules (everything compiled with GCC)
+        (["cmake@3.27.9 %gcc", "foo %clang"], ["%gcc"], [], ["cmake@3.27.9 %gcc"]),
+        # "cmake" discarded by exclude rules (everything compiled with GCC but cmake)
+        (["cmake@3.27.9 %gcc", "foo %gcc"], ["%gcc"], ["cmake"], ["foo %gcc"]),
+    ],
+)
+def test_spec_filters(specs, include, exclude, expected):
+    specs = [Spec(x) for x in specs]
+    expected = [Spec(x) for x in expected]
+    f = spack.solver.asp.SpecFilter(
+        factory=lambda: specs, is_usable=lambda x: True, include=include, exclude=exclude
+    )
+    assert f.selected_specs() == expected

lib/spack/spack/test/concretize_compiler_runtimes.py

@@ -79,13 +79,13 @@ def test_external_nodes_do_not_have_runtimes(runtime_repo, mutable_config, tmp_p
     [
         # The reused runtime is older than we need, thus we'll add a more recent one for a
         ("a%gcc@10.2.1", "b%gcc@9.4.0", {"a": "gcc-runtime@10.2.1", "b": "gcc-runtime@9.4.0"}, 2),
-        # The root is compiled with an older compiler, thus we'll reuse the runtime from b
-        ("a%gcc@9.4.0", "b%gcc@10.2.1", {"a": "gcc-runtime@10.2.1", "b": "gcc-runtime@10.2.1"}, 1),
+        # The root is compiled with an older compiler, thus we'll NOT reuse the runtime from b
+        ("a%gcc@9.4.0", "b%gcc@10.2.1", {"a": "gcc-runtime@9.4.0", "b": "gcc-runtime@9.4.0"}, 1),
         # Same as before, but tests that we can reuse from a more generic target
         pytest.param(
             "a%gcc@9.4.0",
             "b%gcc@10.2.1 target=x86_64",
-            {"a": "gcc-runtime@10.2.1 target=x86_64", "b": "gcc-runtime@10.2.1 target=x86_64"},
+            {"a": "gcc-runtime@9.4.0", "b": "gcc-runtime@9.4.0"},
             1,
             marks=pytest.mark.skipif(
                 str(archspec.cpu.host().family) != "x86_64", reason="test data is x86_64 specific"
@@ -102,13 +102,15 @@ def test_external_nodes_do_not_have_runtimes(runtime_repo, mutable_config, tmp_p
         ),
     ],
 )
+@pytest.mark.regression("44444")
 def test_reusing_specs_with_gcc_runtime(root_str, reused_str, expected, nruntime, runtime_repo):
     """Tests that we can reuse specs with a "gcc-runtime" leaf node. In particular, checks
     that the semantic for gcc-runtimes versions accounts for reused packages too.
+
+    Reusable runtime versions should be lower, or equal, to that of parent nodes.
     """
     root, reused_spec = _concretize_with_reuse(root_str=root_str, reused_str=reused_str)
 
-    assert f"{expected['b']}" in reused_spec
     runtime_a = root.dependencies("gcc-runtime")[0]
     assert runtime_a.satisfies(expected["a"])
     runtime_b = root["b"].dependencies("gcc-runtime")[0]
@@ -123,8 +125,7 @@ def test_reusing_specs_with_gcc_runtime(root_str, reused_str, expected, nruntime
     [
         # Ensure that, whether we have multiple runtimes in the DAG or not,
         # we always link only the latest version
-        ("a%gcc@10.2.1", "b%gcc@9.4.0", ["gcc-runtime@10.2.1"], ["gcc-runtime@9.4.0"]),
-        ("a%gcc@9.4.0", "b%gcc@10.2.1", ["gcc-runtime@10.2.1"], ["gcc-runtime@9.4.0"]),
+        ("a%gcc@10.2.1", "b%gcc@9.4.0", ["gcc-runtime@10.2.1"], ["gcc-runtime@9.4.0"])
     ],
 )
 def test_views_can_handle_duplicate_runtime_nodes(