wrote test case backwards

.flake8

@@ -28,7 +28,7 @@ max-line-length = 99
 # - F821: undefined name `name`
 #
 per-file-ignores =
-  var/spack/*/package.py:F403,F405,F821
+  var/spack/repos/*/package.py:F403,F405,F821
   *-ci-package.py:F403,F405,F821
 
 # exclude things we usually do not want linting for.

.gitattributes

@@ -1,3 +1,4 @@
 *.py diff=python
+*.lp linguist-language=Prolog
 lib/spack/external/* linguist-vendored
-*.bat text eol=crlf
+*.bat text eol=crlf

.github/workflows/audit.yaml

@@ -59,6 +59,7 @@ jobs:
     - 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 configs

.github/workflows/bootstrap.yml

@@ -26,7 +26,7 @@ jobs:
           dnf install -y \
               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 gawk
+              cmake bison bison-devel libstdc++-static
       - name: Setup OpenSUSE
         if: ${{ matrix.image == 'opensuse/leap:latest' }}
         run: |

.github/workflows/ci.yaml

@@ -9,7 +9,6 @@ on:
     branches:
       - develop
       - releases/**
-  merge_group:
 
 concurrency:
   group: ci-${{github.ref}}-${{github.event.pull_request.number || github.run_number}}
@@ -26,33 +25,29 @@ jobs:
       packages: ${{ steps.filter.outputs.packages }}
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-        if: ${{ github.event_name == 'push' || github.event_name == 'merge_group' }}
+        if: ${{ github.event_name == 'push' }}
         with:
           fetch-depth: 0
             # For pull requests it's not necessary to checkout the code
       - uses: dorny/paths-filter@de90cc6fb38fc0963ad72b210f1f284cd68cea36
         id: filter
         with:
-          # For merge group events, compare against the target branch (main)
-          base: ${{ github.event_name == 'merge_group' && github.event.merge_group.base_ref || '' }}
-          # For merge group events, use the merge group head ref
-          ref: ${{ github.event_name == 'merge_group' && github.event.merge_group.head_sha || github.ref }}
           # See https://github.com/dorny/paths-filter/issues/56 for the syntax used below
           # Don't run if we only modified packages in the
           # built-in repository or documentation
           filters: |
             bootstrap:
-            - 'var/spack/repos/spack_repo/builtin/packages/clingo-bootstrap/**'
-            - 'var/spack/repos/spack_repo/builtin/packages/clingo/**'
-            - 'var/spack/repos/spack_repo/builtin/packages/python/**'
-            - 'var/spack/repos/spack_repo/builtin/packages/re2c/**'
-            - 'var/spack/repos/spack_repo/builtin/packages/gnupg/**'
-            - 'var/spack/repos/spack_repo/builtin/packages/libassuan/**'
-            - 'var/spack/repos/spack_repo/builtin/packages/libgcrypt/**'
-            - 'var/spack/repos/spack_repo/builtin/packages/libgpg-error/**'
-            - 'var/spack/repos/spack_repo/builtin/packages/libksba/**'
-            - 'var/spack/repos/spack_repo/builtin/packages/npth/**'
-            - 'var/spack/repos/spack_repo/builtin/packages/pinentry/**'
+            - 'var/spack/repos/builtin/packages/clingo-bootstrap/**'
+            - 'var/spack/repos/builtin/packages/clingo/**'
+            - 'var/spack/repos/builtin/packages/python/**'
+            - 'var/spack/repos/builtin/packages/re2c/**'
+            - 'var/spack/repos/builtin/packages/gnupg/**'
+            - 'var/spack/repos/builtin/packages/libassuan/**'
+            - 'var/spack/repos/builtin/packages/libgcrypt/**'
+            - 'var/spack/repos/builtin/packages/libgpg-error/**'
+            - 'var/spack/repos/builtin/packages/libksba/**'
+            - 'var/spack/repos/builtin/packages/npth/**'
+            - 'var/spack/repos/builtin/packages/pinentry/**'
             - 'lib/spack/**'
             - 'share/spack/**'
             - '.github/workflows/bootstrap.yml'
@@ -81,11 +76,10 @@ jobs:
 
   prechecks:
     needs: [ changes ]
-    uses: ./.github/workflows/prechecks.yml
+    uses: ./.github/workflows/valid-style.yml
     secrets: inherit
     with:
       with_coverage: ${{ needs.changes.outputs.core }}
-      with_packages: ${{ needs.changes.outputs.packages }}
 
   import-check:
     needs: [ changes ]
@@ -99,7 +93,7 @@ jobs:
     - name: Success
       run: |
         if [ "${{ needs.prechecks.result }}" == "failure" ] || [ "${{ needs.prechecks.result }}" == "canceled" ]; then
-          echo "Unit tests failed."
+          echo "Unit tests failed." 
           exit 1
         else
           exit 0
@@ -107,7 +101,6 @@ jobs:
 
   coverage:
     needs: [ unit-tests, prechecks ]
-    if: ${{ needs.changes.outputs.core }}
     uses: ./.github/workflows/coverage.yml
     secrets: inherit
 
@@ -120,10 +113,10 @@ jobs:
     - name: Status summary
       run: |
         if [ "${{ needs.unit-tests.result }}" == "failure" ] || [ "${{ needs.unit-tests.result }}" == "canceled" ]; then
-          echo "Unit tests failed."
+          echo "Unit tests failed." 
           exit 1
         elif [ "${{ needs.bootstrap.result }}" == "failure" ] || [ "${{ needs.bootstrap.result }}" == "canceled" ]; then
-          echo "Bootstrap tests failed."
+          echo "Bootstrap tests failed." 
           exit 1
         else
           exit 0

.github/workflows/import-check.yaml

@@ -39,7 +39,7 @@ jobs:
       uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
       with:
         repository: haampie/circular-import-fighter
-        ref: 4cdb0bf15f04ab6b49041d5ef1bfd9644cce7f33
+        ref: e38bcd0aa46368e30648b61b7f0d8c1ca68aadff
         path: circular-import-fighter
     - name: Install dependencies
       working-directory: circular-import-fighter

.github/workflows/prechecks.yml

@@ -1,108 +0,0 @@
-name: prechecks
-
-on:
-  workflow_call:
-    inputs:
-      with_coverage:
-        required: true
-        type: string
-      with_packages:
-        required: true
-        type: string
-
-concurrency:
-  group: style-${{github.ref}}-${{github.event.pull_request.number || github.run_number}}
-  cancel-in-progress: true
-
-
-jobs:
-  # Validate that the code can be run on all the Python versions supported by Spack
-  validate:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-    - uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b
-      with:
-        python-version: '3.13'
-        cache: 'pip'
-        cache-dependency-path: '.github/workflows/requirements/style/requirements.txt'
-    - name: Install Python Packages
-      run: |
-        pip install -r .github/workflows/requirements/style/requirements.txt
-    - name: vermin (Spack's Core)
-      run: |
-        vermin --backport importlib --backport argparse --violations --backport typing -t=3.6- -vvv lib/spack/spack/ lib/spack/llnl/ bin/
-    - name: vermin (Repositories)
-      run: |
-        vermin --backport importlib --backport argparse --violations --backport typing -t=3.6- -vvv var/spack/repos var/spack/test_repos
-
-  # Run style checks on the files that have been changed
-  style:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-      with:
-        fetch-depth: 2
-    - uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b
-      with:
-        python-version: '3.13'
-        cache: 'pip'
-        cache-dependency-path: '.github/workflows/requirements/style/requirements.txt'
-    - name: Install Python packages
-      run: |
-        pip install -r .github/workflows/requirements/style/requirements.txt
-    - name: Run style tests
-      run: |
-        bin/spack style --base HEAD^1
-        bin/spack license verify
-        pylint -j $(nproc) --disable=all --enable=unspecified-encoding --ignore-paths=lib/spack/external lib
-
-  audit:
-    uses: ./.github/workflows/audit.yaml
-    secrets: inherit
-    with:
-      with_coverage: ${{ inputs.with_coverage }}
-      python_version: '3.13'
-
-  verify-checksums:
-    # do not run if the commit message or PR description contains [skip-verify-checksums]
-    if: >-
-      ${{ inputs.with_packages == 'true' &&
-      !contains(github.event.pull_request.body, '[skip-verify-checksums]') &&
-      !contains(github.event.head_commit.message, '[skip-verify-checksums]') }}
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29
-      with:
-        fetch-depth: 2
-    - name: Verify Added Checksums
-      run: |
-        bin/spack ci verify-versions HEAD^1 HEAD
-
-  # Check that spack can bootstrap the development environment on Python 3.6 - RHEL8
-  bootstrap-dev-rhel8:
-    runs-on: ubuntu-latest
-    container: registry.access.redhat.com/ubi8/ubi
-    steps:
-      - name: Install dependencies
-        run: |
-          dnf install -y \
-              bzip2 curl file gcc-c++ gcc gcc-gfortran git gnupg2 gzip \
-              make patch tcl unzip which xz
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-      - name: Setup repo and non-root user
-        run: |
-          git --version
-          git config --global --add safe.directory '*'
-          git fetch --unshallow
-          . .github/workflows/bin/setup_git.sh
-          useradd spack-test
-          chown -R spack-test .
-      - name: Bootstrap Spack development environment
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          source share/spack/setup-env.sh
-          spack debug report
-          spack -d bootstrap now --dev
-          spack -d style -t black
-          spack unit-test -V

.github/workflows/requirements/style/requirements.txt

@@ -1,8 +1,7 @@
-black==25.1.0
-clingo==5.8.0
-flake8==7.2.0
-isort==6.0.1
-mypy==1.15.0
-types-six==1.17.0.20250403
+black==24.10.0
+clingo==5.7.1
+flake8==7.1.1
+isort==5.13.2
+mypy==1.11.2
+types-six==1.17.0.20241205
 vermin==1.6.0
-pylint==3.3.7

.github/workflows/unit_tests.yaml

@@ -19,6 +19,9 @@ jobs:
         on_develop:
         - ${{ github.ref == 'refs/heads/develop' }}
         include:
+        - python-version: '3.6'
+          os: ubuntu-20.04
+          on_develop: ${{ github.ref == 'refs/heads/develop' }}
         - python-version: '3.7'
           os: ubuntu-22.04
           on_develop: ${{ github.ref == 'refs/heads/develop' }}

.github/workflows/valid-style.yml

@@ -0,0 +1,106 @@
+name: style
+
+on:
+  workflow_call:
+    inputs:
+      with_coverage:
+        required: true
+        type: string
+
+concurrency:
+  group: style-${{github.ref}}-${{github.event.pull_request.number || github.run_number}}
+  cancel-in-progress: true
+
+
+jobs:
+  # Validate that the code can be run on all the Python versions supported by Spack
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+    - uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b
+      with:
+        python-version: '3.13'
+        cache: 'pip'
+    - name: Install Python Packages
+      run: |
+        pip install --upgrade pip setuptools
+        pip install -r .github/workflows/requirements/style/requirements.txt
+    - name: vermin (Spack's Core)
+      run: vermin --backport importlib --backport argparse --violations --backport typing -t=3.6- -vvv lib/spack/spack/ lib/spack/llnl/ bin/
+    - name: vermin (Repositories)
+      run: vermin --backport importlib --backport argparse --violations --backport typing -t=3.6- -vvv var/spack/repos
+  # Run style checks on the files that have been changed
+  style:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      with:
+        fetch-depth: 0
+    - uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b
+      with:
+        python-version: '3.13'
+        cache: 'pip'
+    - name: Install Python packages
+      run: |
+        pip install --upgrade pip setuptools
+        pip install -r .github/workflows/requirements/style/requirements.txt
+    - name: Setup git configuration
+      run: |
+        # Need this for the git tests to succeed.
+        git --version
+        . .github/workflows/bin/setup_git.sh
+    - name: Run style tests
+      run: |
+          share/spack/qa/run-style-tests
+  audit:
+    uses: ./.github/workflows/audit.yaml
+    secrets: inherit
+    with:
+      with_coverage: ${{ inputs.with_coverage }}
+      python_version: '3.13'
+  # Check that spack can bootstrap the development environment on Python 3.6 - RHEL8
+  bootstrap-dev-rhel8:
+    runs-on: ubuntu-latest
+    container: registry.access.redhat.com/ubi8/ubi
+    steps:
+      - name: Install dependencies
+        run: |
+          dnf install -y \
+              bzip2 curl file gcc-c++ gcc gcc-gfortran git gnupg2 gzip \
+              make patch tcl unzip which xz
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      - name: Setup repo and non-root user
+        run: |
+          git --version
+          git config --global --add safe.directory '*'
+          git fetch --unshallow
+          . .github/workflows/bin/setup_git.sh
+          useradd spack-test
+          chown -R spack-test .
+      - name: Bootstrap Spack development environment
+        shell: runuser -u spack-test -- bash {0}
+        run: |
+          source share/spack/setup-env.sh
+          spack debug report
+          spack -d bootstrap now --dev
+          spack -d style -t black
+          spack unit-test -V
+
+  # Further style checks from pylint
+  pylint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b
+        with:
+          python-version: '3.13'
+          cache: 'pip'
+      - name: Install Python packages
+        run: |
+          pip install --upgrade pip setuptools pylint
+      - name: Pylint (Spack Core)
+        run: |
+          pylint -j 4 --disable=all --enable=unspecified-encoding --ignore-paths=lib/spack/external lib

.gitignore

@@ -201,6 +201,7 @@ tramp
 
 # Org-mode
 .org-id-locations
+*_archive
 
 # flymake-mode
 *_flymake.*

README.md

@@ -46,42 +46,18 @@ See the
 [Feature Overview](https://spack.readthedocs.io/en/latest/features.html)
 for examples and highlights.
 
-Installation
-----------------
-
-To install spack, first make sure you have Python & Git.
+To install spack and your first package, make sure you have Python & Git.
 Then:
 
-```bash
-git clone -c feature.manyFiles=true --depth=2 https://github.com/spack/spack.git
-```
-
-<details>
-<summary>What are <code>manyFiles=true</code> and <code>--depth=2</code>?</summary>
-<br>
+    $ git clone -c feature.manyFiles=true --depth=2 https://github.com/spack/spack.git
+    $ cd spack/bin
+    $ ./spack install zlib
 
+> [!TIP]
 > `-c feature.manyFiles=true` improves git's performance on repositories with 1,000+ files.
 >
 > `--depth=2` prunes the git history to reduce the size of the Spack installation.
 
-</details>
-
-```bash
-# For bash/zsh/sh
-. spack/share/spack/setup-env.sh
-
-# For tcsh/csh
-source spack/share/spack/setup-env.csh
-
-# For fish
-. spack/share/spack/setup-env.fish
-```
-
-```bash
-# Now you're ready to install a package!
-spack install zlib-ng
-```
-
 Documentation
 ----------------
 

etc/spack/defaults/concretizer.yaml

@@ -43,28 +43,6 @@ concretizer:
     # (e.g. py-setuptools, cmake etc.)
     # "full" (experimental): allows separation of the entire build-tool stack (e.g. the entire "cmake" subDAG)
     strategy: minimal
-    # Maximum number of duplicates in a DAG, when using a strategy that allows duplicates. "default" is the
-    # number used if there isn't a more specific alternative
-    max_dupes:
-      default: 1
-      # Virtuals
-      c: 2
-      cxx: 2
-      fortran: 1
-      # Regular packages
-      cmake: 2
-      gmake: 2
-      python: 2
-      python-venv: 2
-      py-cython: 2
-      py-flit-core: 2
-      py-pip: 2
-      py-setuptools: 2
-      py-wheel: 2
-      xcb-proto: 2
-      # Compilers
-      gcc: 2
-      llvm: 2
   # Option to specify compatibility between operating systems for reuse of compilers and packages
   # Specified as a key: [list] where the key is the os that is being targeted, and the list contains the OS's
   # it can reuse. Note this is a directional compatibility so mutual compatibility between two OS's
@@ -85,7 +63,3 @@ concretizer:
   # Setting this to false yields unreproducible results, so we advise to use that value only
   # for debugging purposes (e.g. check which constraints can help Spack concretize faster).
   error_on_timeout: true
-
-  # Static analysis may reduce the concretization time by generating smaller ASP problems, in
-  # cases where there are requirements that prevent part of the search space to be explored.
-  static_analysis: false

etc/spack/defaults/config.yaml

@@ -19,7 +19,7 @@ config:
   install_tree:
     root: $spack/opt/spack
     projections:
-      all: "{architecture.platform}-{architecture.target}/{name}-{version}-{hash}"
+      all: "{architecture}/{compiler.name}-{compiler.version}/{name}-{version}-{hash}"
     # install_tree can include an optional padded length (int or boolean)
     # default is False (do not pad)
     # if padded_length is True, Spack will pad as close to the system max path
@@ -90,9 +90,10 @@ config:
   misc_cache: $user_cache_path/cache
 
 
-  # Abort downloads after this many seconds if not data is received.
-  # Setting this to 0 will disable the timeout.
-  connect_timeout: 30
+  # Timeout in seconds used for downloading sources etc. This only applies
+  # to the connection phase and can be increased for slow connections or
+  # servers. 0 means no timeout.
+  connect_timeout: 10
 
 
   # If this is false, tools like curl that use SSL will not verify

etc/spack/defaults/darwin/packages.yaml

@@ -15,18 +15,17 @@
 # -------------------------------------------------------------------------
 packages:
   all:
+    compiler:
+    - apple-clang
+    - clang
+    - gcc
     providers:
-      c: [apple-clang, llvm, gcc]
-      cxx: [apple-clang, llvm, gcc]
       elf: [libelf]
-      fortran: [gcc]
       fuse: [macfuse]
       gl: [apple-gl]
       glu: [apple-glu]
       unwind: [apple-libunwind]
       uuid: [apple-libuuid]
-  apple-clang:
-    buildable: false
   apple-gl:
     buildable: false
     externals:
@@ -51,12 +50,3 @@ packages:
     # although the version number used here isn't critical
     - spec: apple-libuuid@1353.100.2
       prefix: /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk
-  c:
-    prefer:
-    - apple-clang
-  cxx:
-    prefer:
-    - apple-clang
-  fortran:
-    prefer:
-    - gcc

etc/spack/defaults/packages.yaml

@@ -15,18 +15,19 @@
 # -------------------------------------------------------------------------
 packages:
   all:
+    compiler: [gcc, clang, oneapi, xl, nag, fj, aocc]
     providers:
       awk: [gawk]
       armci: [armcimpi]
       blas: [openblas, amdblis]
-      c: [gcc, llvm, intel-oneapi-compilers]
-      cxx: [gcc, llvm, intel-oneapi-compilers]
+      c: [gcc]
+      cxx: [gcc]
       D: [ldc]
       daal: [intel-oneapi-daal]
       elf: [elfutils]
       fftw-api: [fftw, amdfftw]
       flame: [libflame, amdlibflame]
-      fortran: [gcc, llvm, intel-oneapi-compilers]
+      fortran: [gcc]
       fortran-rt: [gcc-runtime, intel-oneapi-runtime]
       fuse: [libfuse]
       gl: [glx, osmesa]
@@ -72,8 +73,6 @@ packages:
     permissions:
       read: world
       write: user
-  cce:
-    buildable: false
   cray-fftw:
     buildable: false
   cray-libsci:
@@ -88,23 +87,13 @@ packages:
     buildable: false
   essl:
     buildable: false
-  fj:
-    buildable: false
   fujitsu-mpi:
     buildable: false
   fujitsu-ssl2:
     buildable: false
-  glibc:
-    buildable: false
   hpcx-mpi:
     buildable: false
-  iconv:
-    prefer: [libiconv]
   mpt:
     buildable: false
-  musl:
-    buildable: false
   spectrum-mpi:
     buildable: false
-  xl:
-    buildable: false

etc/spack/defaults/repos.yaml

@@ -11,4 +11,4 @@
 #   ~/.spack/repos.yaml
 # -------------------------------------------------------------------------
 repos:
-  - $spack/var/spack/repos/spack_repo/builtin
+  - $spack/var/spack/repos/builtin

etc/spack/defaults/windows/packages.yaml

@@ -15,13 +15,8 @@
 # -------------------------------------------------------------------------
 packages:
   all:
+    compiler:
+    - msvc
     providers:
-      c : [msvc]
-      cxx: [msvc]
       mpi: [msmpi]
       gl: [wgl]
-  mpi:
-    require:
-    - one_of: [msmpi]
-  msvc:
-    buildable: false

lib/spack/docs/basic_usage.rst

@@ -1291,61 +1291,55 @@ based on site policies.
 Variants
 ^^^^^^^^
 
-Variants are named options associated with a particular package and are
-typically used to enable or disable certain features at build time. They
-are optional, as each package must provide default values for each variant
-it makes available.
-
-The names of variants available for a particular package depend on
+Variants are named options associated with a particular package. They are
+optional, as each package must provide default values for each variant it
+makes available. Variants can be specified using
+a flexible parameter syntax ``name=<value>``. For example,
+``spack install mercury debug=True`` will install mercury built with debug
+flags. The names of particular variants available for a package depend on
 what was provided by the package author. ``spack info <package>`` will
 provide information on what build variants are available.
 
-There are different types of variants:
+For compatibility with earlier versions, variants which happen to be
+boolean in nature can be specified by a syntax that represents turning
+options on and off. For example, in the previous spec we could have
+supplied ``mercury +debug`` with the same effect of enabling the debug
+compile time option for the libelf package.
 
-1. Boolean variants. Typically used to enable or disable a feature at
-   compile time. For example, a package might have a ``debug`` variant that
-   can be explicitly enabled with ``+debug`` and disabled with ``~debug``.
-2. Single-valued variants. Often used to set defaults. For example, a package
-   might have a ``compression`` variant that determines the default
-   compression algorithm, which users could set to ``compression=gzip`` or
-   ``compression=zstd``.
-3. Multi-valued variants. A package might have a ``fabrics`` variant that
-   determines which network fabrics to support. Users could set this to
-   ``fabrics=verbs,ofi`` to enable both InfiniBand verbs and OpenFabrics
-   interfaces. The values are separated by commas.
+Depending on the package a variant may have any default value.  For
+``mercury`` here, ``debug`` is ``False`` by default, and we turned it on
+with ``debug=True`` or ``+debug``.  If a variant is ``True`` by default
+you can turn it off by either adding ``-name`` or ``~name`` to the spec.
 
-   The meaning of ``fabrics=verbs,ofi`` is to enable *at least* the specified
-   fabrics, but other fabrics may be enabled as well. If the intent is to
-   enable *only* the specified fabrics, then the ``fabrics:=verbs,ofi``
-   syntax should be used with the ``:=`` operator.
+There are two syntaxes here because, depending on context, ``~`` and
+``-`` may mean different things.  In most shells, the following will
+result in the shell performing home directory substitution:
 
-.. note::
+.. code-block:: sh
 
-   In certain shells, the the ``~`` character is expanded to the home
-   directory. To avoid these issues, avoid whitespace between the package
-   name and the variant:
+   mpileaks ~debug   # shell may try to substitute this!
+   mpileaks~debug    # use this instead
 
-   .. code-block:: sh
+If there is a user called ``debug``, the ``~`` will be incorrectly
+expanded.  In this situation, you would want to write ``libelf
+-debug``.  However, ``-`` can be ambiguous when included after a
+package name without spaces:
 
-      mpileaks ~debug   # shell may try to substitute this!
-      mpileaks~debug    # use this instead
+.. code-block:: sh
 
-   Alternatively, you can use the ``-`` character to disable a variant,
-   but be aware that this requires a space between the package name and
-   the variant:
+   mpileaks-debug     # wrong!
+   mpileaks -debug    # right
 
-   .. code-block:: sh
+Spack allows the ``-`` character to be part of package names, so the
+above will be interpreted as a request for the ``mpileaks-debug``
+package, not a request for ``mpileaks`` built without ``debug``
+options.  In this scenario, you should write ``mpileaks~debug`` to
+avoid ambiguity.
 
-      mpileaks-debug     # wrong: refers to a package named "mpileaks-debug"
-      mpileaks -debug    # right: refers to a package named mpileaks with debug disabled
-
-   As a last resort, ``debug=False`` can also be used to disable a boolean variant.
-
-
-
-"""""""""""""""""""""""""""""""""""
-Variant propagation to dependencies
-"""""""""""""""""""""""""""""""""""
+When spack normalizes specs, it prints them out with no spaces boolean
+variants using the backwards compatibility syntax and uses only ``~``
+for disabled boolean variants.  The ``-`` and spaces on the command
+line are provided for convenience and legibility.
 
 Spack allows variants to propagate their value to the package's
 dependency by using ``++``, ``--``, and ``~~`` for boolean variants.
@@ -1415,29 +1409,27 @@ that executables will run without the need to set ``LD_LIBRARY_PATH``.
 
 .. code-block:: yaml
 
-  packages:
-    gcc:
-      externals:
-      - spec: gcc@4.9.3
-        prefix: /opt/gcc
-        extra_attributes:
-          compilers:
-            c: /opt/gcc/bin/gcc
-            cxx: /opt/gcc/bin/g++
-            fortran: /opt/gcc/bin/gfortran
-          environment:
-            unset:
-              - BAD_VARIABLE
-            set:
-              GOOD_VARIABLE_NUM: 1
-              GOOD_VARIABLE_STR: good
-            prepend_path:
-              PATH: /path/to/binutils
-            append_path:
-              LD_LIBRARY_PATH: /opt/gcc/lib
-          extra_rpaths:
-          - /path/to/some/compiler/runtime/directory
-          - /path/to/some/other/compiler/runtime/directory
+  compilers:
+    - compiler:
+        spec: gcc@4.9.3
+        paths:
+          cc: /opt/gcc/bin/gcc
+          c++: /opt/gcc/bin/g++
+          f77: /opt/gcc/bin/gfortran
+          fc: /opt/gcc/bin/gfortran
+        environment:
+          unset:
+            - BAD_VARIABLE
+          set:
+            GOOD_VARIABLE_NUM: 1
+            GOOD_VARIABLE_STR: good
+          prepend_path:
+            PATH: /path/to/binutils
+          append_path:
+            LD_LIBRARY_PATH: /opt/gcc/lib
+        extra_rpaths:
+        - /path/to/some/compiler/runtime/directory
+        - /path/to/some/other/compiler/runtime/directory
 
 
 ^^^^^^^^^^^^^^^^^^^^^^^
@@ -1769,24 +1761,19 @@ Verifying installations
 The ``spack verify`` command can be used to verify the validity of
 Spack-installed packages any time after installation.
 
-
-^^^^^^^^^^^^^^^^^^^^^^^^^
-``spack verify manifest``
-^^^^^^^^^^^^^^^^^^^^^^^^^
-
 At installation time, Spack creates a manifest of every file in the
 installation prefix. For links, Spack tracks the mode, ownership, and
 destination. For directories, Spack tracks the mode, and
 ownership. For files, Spack tracks the mode, ownership, modification
-time, hash, and size. The ``spack verify manifest`` command will check,
-for every file in each package, whether any of those attributes have
-changed. It will also check for newly added files or deleted files from
-the installation prefix. Spack can either check all installed packages
+time, hash, and size. The Spack verify command will check, for every
+file in each package, whether any of those attributes have changed. It
+will also check for newly added files or deleted files from the
+installation prefix. Spack can either check all installed packages
 using the `-a,--all` or accept specs listed on the command line to
 verify.
 
-The ``spack verify manifest`` command can also verify for individual files
-that they haven't been altered since installation time. If the given file
+The ``spack verify`` command can also verify for individual files that
+they haven't been altered since installation time. If the given file
 is not in a Spack installation prefix, Spack will report that it is
 not owned by any package. To check individual files instead of specs,
 use the ``-f,--files`` option.
@@ -1801,22 +1788,6 @@ 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.
 
-^^^^^^^^^^^^^^^^^^^^^^^^^^
-``spack verify libraries``
-^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-The ``spack verify libraries`` command can be used to verify that packages
-do not have accidental system dependencies. This command scans the install
-prefixes of packages for executables and shared libraries, and resolves
-their needed libraries in their RPATHs. When needed libraries cannot be
-located, an error is reported. This typically indicates that a package
-was linked against a system library, instead of a library provided by
-a Spack package.
-
-This verification can also be enabled as a post-install hook by setting
-``config:shared_linking:missing_library_policy`` to ``error`` or ``warn``
-in :ref:`config.yaml <config-yaml>`.
-
 -----------------------
 Filesystem requirements
 -----------------------
@@ -1916,7 +1887,7 @@ diagnostics. Issues, if found, are reported to stdout:
    PKG-DIRECTIVES: 1 issue found
    1. lammps: wrong variant in "conflicts" directive
        the variant 'adios' does not exist
-       in /home/spack/spack/var/spack/repos/spack_repo/builtin/packages/lammps/package.py
+       in /home/spack/spack/var/spack/repos/builtin/packages/lammps/package.py
 
 
 ------------

lib/spack/docs/build_settings.rst

@@ -34,6 +34,7 @@ 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
+3. ``namespaces``: list of namespaces from which to reuse specs, or the string ``"any"``.
 
 Each source in ``from`` is itself an object:
 
@@ -56,6 +57,7 @@ For instance, the following configuration:
    concretizer:
      reuse:
        roots: true
+       namespaces: [builtin]
        from:
        - type: local
          include:
@@ -63,7 +65,8 @@ For instance, the following configuration:
          - "%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.
+in the local store. Any spec from remote buildcaches is disregarded. Any spec from a namespace other than
+Spack's builtin repo is disregarded.
 
 To reduce the boilerplate in configuration files, default values for the ``include`` and
 ``exclude`` options can be pushed up one level:

lib/spack/docs/build_systems.rst

@@ -63,6 +63,7 @@ on these ideas for each distinct build system that Spack supports:
    build_systems/cudapackage
    build_systems/custompackage
    build_systems/inteloneapipackage
+   build_systems/intelpackage
    build_systems/rocmpackage
    build_systems/sourceforgepackage
 
@@ -83,7 +84,7 @@ packages. You can quickly find examples by running:
 
 .. code-block:: console
 
-   $ cd var/spack/repos/spack_repo/builtin/packages
+   $ cd var/spack/repos/builtin/packages
    $ grep -l QMakePackage */package.py
 
 

lib/spack/docs/build_systems/bundlepackage.rst

@@ -27,10 +27,10 @@ it could use the ``require`` directive as follows:
 
 Spack has a number of built-in bundle packages, such as:
 
-* `AmdAocl <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/amd_aocl/package.py>`_
-* `EcpProxyApps <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/ecp_proxy_apps/package.py>`_
-* `Libc <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/libc/package.py>`_
-* `Xsdk <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/xsdk/package.py>`_
+* `AmdAocl <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/amd-aocl/package.py>`_
+* `EcpProxyApps <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/ecp-proxy-apps/package.py>`_
+* `Libc <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/libc/package.py>`_
+* `Xsdk <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/xsdk/package.py>`_
 
 where ``Xsdk`` also inherits from ``CudaPackage`` and ``RocmPackage`` and
 ``Libc`` is a virtual bundle package for the C standard library.

lib/spack/docs/build_systems/cmakepackage.rst

@@ -199,7 +199,7 @@ a variant to control this:
 However, not every CMake package accepts all four of these options.
 Grep the ``CMakeLists.txt`` file to see if the default values are
 missing or replaced. For example, the
-`dealii <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/dealii/package.py>`_
+`dealii <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/dealii/package.py>`_
 package overrides the default variant with:
 
 .. code-block:: python

lib/spack/docs/build_systems/custompackage.rst

@@ -20,8 +20,8 @@ start is to look at the definitions of other build systems. This guide
 focuses mostly on how Spack's build systems work.
 
 In this guide, we will be using the
-`perl <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/perl/package.py>`_ and
-`cmake <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/cmake/package.py>`_
+`perl <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/perl/package.py>`_ and
+`cmake <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/cmake/package.py>`_
 packages as examples. ``perl``'s build system is a hand-written
 ``Configure`` shell script, while ``cmake`` bootstraps itself during
 installation. Both of these packages require custom build systems.

lib/spack/docs/build_systems/inteloneapipackage.rst

@@ -33,6 +33,9 @@ For more information on a specific package, do::
 
   spack info --all <package-name>
 
+Intel no longer releases new versions of Parallel Studio, which can be
+used in Spack via the :ref:`intelpackage`. All of its components can
+now be found in oneAPI.
 
 Examples
 ========
@@ -47,8 +50,34 @@ Install the oneAPI compilers::
 
   spack install intel-oneapi-compilers
 
+Add the compilers to your ``compilers.yaml`` so spack can use them::
 
-To build the ``patchelf`` Spack package with ``icx``, do::
+  spack compiler add `spack location -i intel-oneapi-compilers`/compiler/latest/bin
+
+Verify that the compilers are available::
+
+  spack compiler list
+
+Note that 2024 and later releases do not include ``icc``. Before 2024,
+the package layout was different::
+  
+  spack compiler add `spack location -i intel-oneapi-compilers`/compiler/latest/linux/bin/intel64
+  spack compiler add `spack location -i intel-oneapi-compilers`/compiler/latest/linux/bin
+
+The ``intel-oneapi-compilers`` package includes 2 families of
+compilers:
+
+* ``intel``: ``icc``, ``icpc``, ``ifort``. Intel's *classic*
+  compilers. 2024 and later releases contain ``ifort``, but not
+  ``icc`` and ``icpc``.
+* ``oneapi``: ``icx``, ``icpx``, ``ifx``. Intel's new generation of
+  compilers based on LLVM.
+
+To build the ``patchelf`` Spack package with ``icc``, do::
+
+  spack install patchelf%intel
+
+To build with with ``icx``, do ::
 
   spack install patchelf%oneapi
 
@@ -63,6 +92,15 @@ Install the oneAPI compilers::
 
   spack install intel-oneapi-compilers
 
+Add the compilers to your ``compilers.yaml`` so Spack can use them::
+
+  spack compiler add `spack location -i intel-oneapi-compilers`/compiler/latest/bin
+  spack compiler add `spack location -i intel-oneapi-compilers`/compiler/latest/bin
+
+Verify that the compilers are available::
+
+  spack compiler list
+
 Clone `spack-configs <https://github.com/spack/spack-configs>`_ repo and activate Intel oneAPI CPU environment::
 
   git clone https://github.com/spack/spack-configs
@@ -111,7 +149,7 @@ Compilers
 ---------
 
 To use the compilers, add some information about the installation to
-``packages.yaml``. For most users, it is sufficient to do::
+``compilers.yaml``. For most users, it is sufficient to do::
 
   spack compiler add /opt/intel/oneapi/compiler/latest/bin
 
@@ -119,7 +157,7 @@ Adapt the paths above if you did not install the tools in the default
 location. After adding the compilers, using them is the same
 as if you had installed the ``intel-oneapi-compilers`` package.
 Another option is to manually add the configuration to
-``packages.yaml`` as described in :ref:`Compiler configuration
+``compilers.yaml`` as described in :ref:`Compiler configuration
 <compiler-config>`.
 
 Before 2024, the directory structure was different::
@@ -162,5 +200,15 @@ You can also use Spack-installed libraries. For example::
 Will update your environment CPATH, LIBRARY_PATH, and other
 environment variables for building an application with oneMKL.
 
+More information
+================
+
+This section describes basic use of oneAPI, especially if it has
+changed compared to Parallel Studio. See :ref:`intelpackage` for more
+information on :ref:`intel-virtual-packages`,
+:ref:`intel-unrelated-packages`,
+:ref:`intel-integrating-external-libraries`, and
+:ref:`using-mkl-tips`.
+
 
 .. _`Intel installers`: https://software.intel.com/content/www/us/en/develop/documentation/installation-guide-for-intel-oneapi-toolkits-linux/top.html

lib/spack/docs/build_systems/makefilepackage.rst

@@ -91,14 +91,14 @@ there are any other variables you need to set, you can do this in the
 
 .. code-block:: python
 
-   def setup_build_environment(self, env: EnvironmentModifications) -> None:
+   def setup_build_environment(self, env):
        env.set("PREFIX", prefix)
        env.set("BLASLIB", spec["blas"].libs.ld_flags)
 
 
-`cbench <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/cbench/package.py>`_
+`cbench <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/cbench/package.py>`_
 is a good example of a simple package that does this, while
-`esmf <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/esmf/package.py>`_
+`esmf <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/esmf/package.py>`_
 is a good example of a more complex package.
 
 """"""""""""""""""""""
@@ -129,7 +129,7 @@ If you do need access to the spec, you can create a property like so:
        ]
 
 
-`cloverleaf <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/cloverleaf/package.py>`_
+`cloverleaf <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/cloverleaf/package.py>`_
 is a good example of a package that uses this strategy.
 
 """""""""""""
@@ -152,7 +152,7 @@ and a ``filter`` method to help with this. For example:
        makefile.filter(r"^\s*FC\s*=.*",  f"FC = {spack_fc}")
 
 
-`stream <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/stream/package.py>`_
+`stream <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/stream/package.py>`_
 is a good example of a package that involves editing a Makefile to set
 the appropriate variables.
 
@@ -192,7 +192,7 @@ well for storing variables:
                inc.write(f"{key} = {config[key]}\n")
 
 
-`elk <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/elk/package.py>`_
+`elk <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/elk/package.py>`_
 is a good example of a package that uses a dictionary to store
 configuration variables.
 
@@ -213,7 +213,7 @@ them in a list:
                inc.write(f"{var}\n")
 
 
-`hpl <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/hpl/package.py>`_
+`hpl <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/hpl/package.py>`_
 is a good example of a package that uses a list to store
 configuration variables.
 

lib/spack/docs/build_systems/rocmpackage.rst

@@ -12,7 +12,8 @@ The ``ROCmPackage`` is not a build system but a helper package. Like ``CudaPacka
 it provides standard variants, dependencies, and conflicts to facilitate building
 packages using GPUs though for AMD in this case.
 
-You can find the source for this package (and suggestions for setting up your ``packages.yaml`` file) at
+You can find the source for this package (and suggestions for setting up your
+``compilers.yaml`` and ``packages.yaml`` files) at
 `<https://github.com/spack/spack/blob/develop/lib/spack/spack/build_systems/rocm.py>`__.
 
 ^^^^^^^^

lib/spack/docs/build_systems/rpackage.rst

@@ -39,7 +39,7 @@ for "CRAN <package-name>" and you should quickly find what you want.
 If it isn't on CRAN, try Bioconductor, another common R repository.
 
 For the purposes of this tutorial, we will be walking through
-`r-caret <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/r_caret/package.py>`_
+`r-caret <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/r-caret/package.py>`_
 as an example. If you search for "CRAN caret", you will quickly find what
 you are looking for at https://cran.r-project.org/package=caret.
 https://cran.r-project.org is the main CRAN website. However, CRAN also
@@ -337,7 +337,7 @@ Non-R dependencies
 ^^^^^^^^^^^^^^^^^^
 
 Some packages depend on non-R libraries for linking. Check out the
-`r-stringi <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/r_stringi/package.py>`_
+`r-stringi <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/r-stringi/package.py>`_
 package for an example: https://cloud.r-project.org/package=stringi.
 If you search for the text "SystemRequirements", you will see:
 
@@ -352,7 +352,7 @@ Passing arguments to the installation
 
 Some R packages provide additional flags that can be passed to
 ``R CMD INSTALL``, often to locate non-R dependencies.
-`r-rmpi <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/r_rmpi/package.py>`_
+`r-rmpi <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/r-rmpi/package.py>`_
 is an example of this, and flags for linking to an MPI library. To pass
 these to the installation command, you can override ``configure_args``
 like so:

lib/spack/docs/build_systems/sconspackage.rst

@@ -104,10 +104,10 @@ Finding available options
 
 The first place to start when looking for a list of valid options to
 build a package is ``scons --help``. Some packages like
-`kahip <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/kahip/package.py>`_
+`kahip <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/kahip/package.py>`_
 don't bother overwriting the default SCons help message, so this isn't
 very useful, but other packages like
-`serf <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/serf/package.py>`_
+`serf <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/serf/package.py>`_
 print a list of valid command-line variables:
 
 .. code-block:: console
@@ -177,7 +177,7 @@ print a list of valid command-line variables:
 
 
 More advanced packages like
-`cantera <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/cantera/package.py>`_
+`cantera <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/cantera/package.py>`_
 use ``scons --help`` to print a list of subcommands:
 
 .. code-block:: console

lib/spack/docs/conf.py

@@ -223,16 +223,6 @@ def setup(sphinx):
     ("py:class", "spack.compiler.CompilerCache"),
     # TypeVar that is not handled correctly
     ("py:class", "llnl.util.lang.T"),
-    ("py:class", "llnl.util.lang.KT"),
-    ("py:class", "llnl.util.lang.VT"),
-    ("py:class", "llnl.util.lang.K"),
-    ("py:class", "llnl.util.lang.V"),
-    ("py:class", "llnl.util.lang.ClassPropertyType"),
-    ("py:obj", "llnl.util.lang.KT"),
-    ("py:obj", "llnl.util.lang.VT"),
-    ("py:obj", "llnl.util.lang.ClassPropertyType"),
-    ("py:obj", "llnl.util.lang.K"),
-    ("py:obj", "llnl.util.lang.V"),
 ]
 
 # The reST default role (used for this markup: `text`) to use for all documents.

lib/spack/docs/config_yaml.rst

@@ -125,8 +125,6 @@ are stored in ``$spack/var/spack/cache``.  These are stored indefinitely
 by default. Can be purged with :ref:`spack clean --downloads
 <cmd-spack-clean>`.
 
-.. _Misc Cache:
-
 --------------------
 ``misc_cache``
 --------------------
@@ -148,16 +146,15 @@ this can expose you to attacks.  Use at your own risk.
 ``ssl_certs``
 --------------------
 
-Path to custom certificats for SSL verification. The value can be a
+Path to custom certificats for SSL verification. The value can be a 
 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.
 When ``url_fetch_method:curl`` the ``config:ssl_certs`` should resolve to
 a single file.  Spack will then set the environment variable ``CURL_CA_BUNDLE``
-in the subprocess calling ``curl``. If additional ``curl`` arguments are required,
-they can be set in the config, e.g. ``url_fetch_method:'curl -k -q'``.
-If ``url_fetch_method:urllib`` then files and directories are supported i.e.
+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.
@@ -337,52 +334,3 @@ create a new alias called ``inst`` that will always call ``install -v``:
 
    aliases:
      inst: install -v
-
--------------------------------
-``concretization_cache:enable``
--------------------------------
-
-When set to ``true``, Spack will utilize a cache of solver outputs from
-successful concretization runs. When enabled, Spack will check the concretization
-cache prior to running the solver. If a previous request to solve a given
-problem is present in the cache, Spack will load the concrete specs and other
-solver data from the cache rather than running the solver. Specs not previously
-concretized will be added to the cache on a successful solve. The cache additionally
-holds solver statistics, so commands like ``spack solve`` will still return information
-about the run that produced a given solver result.
-
-This cache is a subcache of the :ref:`Misc Cache` and as such will be cleaned when the Misc
-Cache is cleaned.
-
-When ``false`` or ommitted, all concretization requests will be performed from scatch
-
-----------------------------
-``concretization_cache:url``
-----------------------------
-
-Path to the location where Spack will root the concretization cache. Currently this only supports
-paths on the local filesystem.
-
-Default location is under the :ref:`Misc Cache` at: ``$misc_cache/concretization``
-
-------------------------------------
-``concretization_cache:entry_limit``
-------------------------------------
-
-Sets a limit on the number of concretization results that Spack will cache. The limit is evaluated
-after each concretization run; if Spack has stored more results than the limit allows, the
-oldest concretization results are pruned until 10% of the limit has been removed.
-
-Setting this value to 0 disables the automatic pruning. It is expected users will be
-responsible for maintaining this cache.
-
------------------------------------
-``concretization_cache:size_limit``
------------------------------------
-
-Sets a limit on the size of the concretization cache in bytes. The limit is evaluated
-after each concretization run; if Spack has stored more results than the limit allows, the
-oldest concretization results are pruned until 10% of the limit has been removed.
-
-Setting this value to 0 disables the automatic pruning. It is expected users will be
-responsible for maintaining this cache.

lib/spack/docs/configuration.rst

@@ -11,10 +11,9 @@ Configuration Files
 Spack has many configuration files.  Here is a quick list of them, in
 case you want to skip directly to specific docs:
 
-* :ref:`packages.yaml <compiler-config>`
+* :ref:`compilers.yaml <compiler-config>`
 * :ref:`concretizer.yaml <concretizer-options>`
 * :ref:`config.yaml <config-yaml>`
-* :ref:`include.yaml <include-yaml>`
 * :ref:`mirrors.yaml <mirrors>`
 * :ref:`modules.yaml <modules>`
 * :ref:`packages.yaml <packages-config>`
@@ -46,12 +45,6 @@ Each Spack configuration file is nested under a top-level section
 corresponding to its name. So, ``config.yaml`` starts with ``config:``,
 ``mirrors.yaml`` starts with ``mirrors:``, etc.
 
-.. tip::
-
-   Validation and autocompletion of Spack config files can be enabled in
-   your editor with the YAML language server. See `spack/schemas
-   <https://github.com/spack/schemas>`_ for more information.
-
 .. _configuration-scopes:
 
 --------------------
@@ -101,7 +94,7 @@ are six configuration scopes. From lowest to highest:
    precedence over all other scopes.
 
 Each configuration directory may contain several configuration files,
-such as ``config.yaml``, ``packages.yaml``, or ``mirrors.yaml``.  When
+such as ``config.yaml``, ``compilers.yaml``, or ``mirrors.yaml``.  When
 configurations conflict, settings from higher-precedence scopes override
 lower-precedence settings.
 

lib/spack/docs/contribution_guide.rst

@@ -226,9 +226,9 @@ If all is well, you'll see something like this:
 
    Modified files:
 
-     var/spack/repos/spack_repo/builtin/packages/hdf5/package.py
-     var/spack/repos/spack_repo/builtin/packages/hdf/package.py
-     var/spack/repos/spack_repo/builtin/packages/netcdf/package.py
+     var/spack/repos/builtin/packages/hdf5/package.py
+     var/spack/repos/builtin/packages/hdf/package.py
+     var/spack/repos/builtin/packages/netcdf/package.py
    =======================================================
    Flake8 checks were clean.
 
@@ -236,9 +236,9 @@ However, if you aren't compliant with PEP 8, flake8 will complain:
 
 .. code-block:: console
 
-   var/spack/repos/spack_repo/builtin/packages/netcdf/package.py:26: [F401] 'os' imported but unused
-   var/spack/repos/spack_repo/builtin/packages/netcdf/package.py:61: [E303] too many blank lines (2)
-   var/spack/repos/spack_repo/builtin/packages/netcdf/package.py:106: [E501] line too long (92 > 79 characters)
+   var/spack/repos/builtin/packages/netcdf/package.py:26: [F401] 'os' imported but unused
+   var/spack/repos/builtin/packages/netcdf/package.py:61: [E303] too many blank lines (2)
+   var/spack/repos/builtin/packages/netcdf/package.py:106: [E501] line too long (92 > 79 characters)
    Flake8 found errors.
 
 Most of the error messages are straightforward, but if you don't understand what
@@ -280,7 +280,7 @@ All of these can be installed with Spack, e.g.
 
 .. warning::
 
-   Sphinx has `several required dependencies <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/py-sphinx/package.py>`_.
+   Sphinx has `several required dependencies <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/py-sphinx/package.py>`_.
    If you're using a ``python`` from Spack and you installed
    ``py-sphinx`` and friends, you need to make them available to your
    ``python``. The easiest way to do this is to run:

lib/spack/docs/developer_guide.rst

@@ -154,7 +154,9 @@ Package-related modules
 
 :mod:`spack.util.naming`
   Contains functions for mapping between Spack package names,
-  Python module names, and Python class names.
+  Python module names, and Python class names. Functions like
+  :func:`~spack.util.naming.mod_to_class` handle mapping package
+  module names to class names.
 
 :mod:`spack.directives`
   *Directives* are functions that can be called inside a package definition

lib/spack/docs/env_vars_yaml.rst

@@ -1,34 +0,0 @@
-.. Copyright Spack Project Developers. See COPYRIGHT file for details.
-
-   SPDX-License-Identifier: (Apache-2.0 OR MIT)
-
-.. _env-vars-yaml:
-
-=============================================
-Environment Variable Settings (env_vars.yaml)
-=============================================
-
-Spack allows you to include shell environment variable modifications
-for a spack environment by including an ``env_vars.yaml``.  Environment
-varaibles can be modified by setting, unsetting, appending, and prepending
-variables in the shell environment.
-The changes to the shell environment will take effect when the spack
-environment is activated.
-
-for example,
-
-.. code-block:: yaml
-
-  env_vars:
-    set:
-      ENVAR_TO_SET_IN_ENV_LOAD: "FOO"
-    unset:
-      ENVAR_TO_UNSET_IN_ENV_LOAD:
-    prepend_path:
-      PATH_LIST: "path/to/prepend"
-    append_path:
-      PATH_LIST: "path/to/append"
-    remove_path:
-      PATH_LIST: "path/to/remove"
-
-

lib/spack/docs/environments.rst

@@ -457,13 +457,6 @@ developed package in the environment are concretized to match the
 version (and other constraints) passed as the spec argument to the
 ``spack develop`` command.
 
-When working deep in the graph it is often desirable to have multiple specs marked
-as ``develop`` so you don't have to restage and/or do full rebuilds each time you
-call ``spack install``.  The ``--recursive`` flag can be used in these scenarios
-to ensure that all the dependents of the initial spec you provide are also marked
-as develop specs.  The ``--recursive`` flag requires a pre-concretized environment
-so the graph can be traversed from the supplied spec all the way to the root specs.
-
 For packages with ``git`` attributes, git branches, tags, and commits can
 also be used as valid concrete versions (see :ref:`version-specifier`).
 This means that for a package ``foo``, ``spack develop foo@git.main`` will clone
@@ -667,56 +660,34 @@ a ``packages.yaml`` file) could contain:
      # ...
      packages:
        all:
-         providers:
-           mpi: [openmpi]
+         compiler: [intel]
      # ...
 
-This configuration sets the default mpi provider to be openmpi.
+This configuration sets the default compiler for all packages to
+``intel``.
 
 ^^^^^^^^^^^^^^^^^^^^^^^
 Included configurations
 ^^^^^^^^^^^^^^^^^^^^^^^
 
-Spack environments allow an ``include`` heading in their yaml schema.
-This heading pulls in external configuration files and applies them to
-the environment.
+Spack environments allow an ``include`` heading in their yaml
+schema. This heading pulls in external configuration files and applies
+them to the environment.
 
 .. code-block:: yaml
 
    spack:
      include:
-     - environment/relative/path/to/config.yaml
-     - path: https://github.com/path/to/raw/config/compilers.yaml
-       sha256: 26e871804a92cd07bb3d611b31b4156ae93d35b6a6d6e0ef3a67871fcb1d258b
+     - relative/path/to/config.yaml
+     - https://github.com/path/to/raw/config/compilers.yaml
      - /absolute/path/to/packages.yaml
-     - path: /path/to/$os/$target/environment
-       optional: true
-     - path: /path/to/os-specific/config-dir
-       when: os == "ventura"
-
-Included configuration files are required *unless* they are explicitly optional
-or the entry's condition evaluates to ``false``. Optional includes are specified
-with the ``optional`` clause and conditional with the ``when`` clause. (See
-:ref:`include-yaml` for more information on optional and conditional entries.)
-
-Files are listed using paths to individual files or directories containing them.
-Path entries may be absolute or relative to the environment or specified as 
-URLs. URLs to individual files must link to the **raw** form of the file's 
-contents (e.g., `GitHub
-<https://docs.github.com/en/repositories/working-with-files/using-files/viewing-and-understanding-files#viewing-or-copying-the-raw-file-content>`_ 
-or `GitLab
-<https://docs.gitlab.com/ee/api/repository_files.html#get-raw-file-from-repository>`_) **and** include a valid sha256 for the file.
-Only the ``file``, ``ftp``, ``http`` and ``https`` protocols (or schemes) are
-supported. Spack-specific, environment and user path variables can be used.
-(See :ref:`config-file-variables` for more information.)
-
-.. warning::
-
-   Recursive includes are not currently processed in a breadth-first manner
-   so the value of a configuration option that is altered by multiple included
-   files may not be what you expect. This will be addressed in a future
-   update.
 
+Environments can include files or URLs. File paths can be relative or
+absolute. URLs include the path to the text for individual files or
+can be the path to a directory containing configuration files.
+Spack supports ``file``, ``http``, ``https`` and ``ftp`` protocols (or
+schemes). Spack-specific, environment and user path variables may be
+used in these paths. See :ref:`config-file-variables` for more information.
 
 ^^^^^^^^^^^^^^^^^^^^^^^^
 Configuration precedence
@@ -1000,28 +971,6 @@ For example, the following environment has three root packages:
 This allows for a much-needed reduction in redundancy between packages
 and constraints.
 
--------------------------------
-Modifying Environment Variables
--------------------------------
-
-Spack Environments can modify the active shell's environment variables when activated.  The environment can be
-configured to set, unset, prepend, or append using ``env_vars`` configuration in the ``spack.yaml``  or through config scopes
-file:
-
-.. code-block:: yaml
-
-  spack:
-    env_vars:
-      set:
-        ENVAR_TO_SET_IN_ENV_LOAD: "FOO"
-      unset:
-        ENVAR_TO_UNSET_IN_ENV_LOAD:
-      prepend_path:
-        PATH_LIST: "path/to/prepend"
-      append_path:
-        PATH_LIST: "path/to/append"
-      remove_path:
-        PATH_LIST: "path/to/remove"
 
 -----------------
 Environment Views

lib/spack/docs/example_files/spack.yaml

@@ -0,0 +1,161 @@
+spack:
+  definitions:
+  - compiler-pkgs:
+    - 'llvm+clang@6.0.1 os=centos7'
+    - 'gcc@6.5.0 os=centos7'
+    - 'llvm+clang@6.0.1 os=ubuntu18.04'
+    - 'gcc@6.5.0 os=ubuntu18.04'
+  - pkgs:
+    - readline@7.0
+    # - xsdk@0.4.0
+  - compilers:
+    - '%gcc@5.5.0'
+    - '%gcc@6.5.0'
+    - '%gcc@7.3.0'
+    - '%clang@6.0.0'
+    - '%clang@6.0.1'
+  - oses:
+    - os=ubuntu18.04
+    - os=centos7
+
+  specs:
+  - matrix:
+    - [$pkgs]
+    - [$compilers]
+    - [$oses]
+    exclude:
+      - '%gcc@7.3.0 os=centos7'
+      - '%gcc@5.5.0 os=ubuntu18.04'
+
+  mirrors:
+    cloud_gitlab: https://mirror.spack.io
+
+  compilers:
+    # The .gitlab-ci.yml for this project picks a Docker container which does
+    # not have any compilers pre-built and ready to use, so we need to fake the
+    # existence of those here.
+    - compiler:
+        operating_system: centos7
+        modules: []
+        paths:
+          cc: /not/used
+          cxx: /not/used
+          f77: /not/used
+          fc: /not/used
+        spec: gcc@5.5.0
+        target: x86_64
+    - compiler:
+        operating_system: centos7
+        modules: []
+        paths:
+          cc: /not/used
+          cxx: /not/used
+          f77: /not/used
+          fc: /not/used
+        spec: gcc@6.5.0
+        target: x86_64
+    - compiler:
+        operating_system: centos7
+        modules: []
+        paths:
+          cc: /not/used
+          cxx: /not/used
+          f77: /not/used
+          fc: /not/used
+        spec: clang@6.0.0
+        target: x86_64
+    - compiler:
+        operating_system: centos7
+        modules: []
+        paths:
+          cc: /not/used
+          cxx: /not/used
+          f77: /not/used
+          fc: /not/used
+        spec: clang@6.0.1
+        target: x86_64
+
+    - compiler:
+        operating_system: ubuntu18.04
+        modules: []
+        paths:
+          cc: /not/used
+          cxx: /not/used
+          f77: /not/used
+          fc: /not/used
+        spec: clang@6.0.0
+        target: x86_64
+    - compiler:
+        operating_system: ubuntu18.04
+        modules: []
+        paths:
+          cc: /not/used
+          cxx: /not/used
+          f77: /not/used
+          fc: /not/used
+        spec: clang@6.0.1
+        target: x86_64
+    - compiler:
+        operating_system: ubuntu18.04
+        modules: []
+        paths:
+          cc: /not/used
+          cxx: /not/used
+          f77: /not/used
+          fc: /not/used
+        spec: gcc@6.5.0
+        target: x86_64
+    - compiler:
+        operating_system: ubuntu18.04
+        modules: []
+        paths:
+          cc: /not/used
+          cxx: /not/used
+          f77: /not/used
+          fc: /not/used
+        spec: gcc@7.3.0
+        target: x86_64
+
+  gitlab-ci:
+    bootstrap:
+      - name: compiler-pkgs
+        compiler-agnostic: true
+    mappings:
+      - # spack-cloud-ubuntu
+        match:
+          # these are specs, if *any* match the spec under consideration, this
+          # 'mapping' will be used to generate the CI job
+          - os=ubuntu18.04
+        runner-attributes:
+          # 'tags' and 'image' go directly onto the job, 'variables' will
+          # be added to what we already necessarily create for the job as
+          # a part of the CI workflow
+          tags:
+            - spack-k8s
+          image:
+            name: scottwittenburg/spack_builder_ubuntu_18.04
+            entrypoint: [""]
+      - # spack-cloud-centos
+        match:
+          # these are specs, if *any* match the spec under consideration, this
+          # 'mapping' will be used to generate the CI job
+          - 'os=centos7'
+        runner-attributes:
+          tags:
+            - spack-k8s
+          image:
+            name: scottwittenburg/spack_builder_centos_7
+            entrypoint: [""]
+
+  cdash:
+    build-group: Release Testing
+    url: http://cdash
+    project: Spack Testing
+    site: Spack Docker-Compose Workflow
+
+  repos: []
+  upstreams: {}
+  modules:
+    enable: []
+  packages: {}
+  config: {}

lib/spack/docs/features.rst

@@ -131,7 +131,7 @@ creates a simple python file:
 It doesn't take much python coding to get from there to a working
 package:
 
-.. literalinclude:: _spack_root/var/spack/repos/spack_repo/builtin/packages/libelf/package.py
+.. literalinclude:: _spack_root/var/spack/repos/builtin/packages/libelf/package.py
    :lines: 5-
 
 Spack also provides wrapper functions around common commands like

lib/spack/docs/frequently_asked_questions.rst

@@ -30,7 +30,7 @@ than always choosing the latest versions or default variants.
 
 .. note::
 
-    As a rule of thumb: requirements + constraints > strong preferences > reuse > preferences > defaults.
+    As a rule of thumb: requirements + constraints > reuse > preferences > defaults.
 
 The following set of criteria (from lowest to highest precedence) explain
 common cases where concretization output may seem surprising at first.
@@ -56,19 +56,7 @@ common cases where concretization output may seem surprising at first.
       concretizer:
         reuse: dependencies  # other options are 'true' and 'false'
 
-3. :ref:`Strong preferences <package-strong-preferences>` configured in ``packages.yaml``
-   are higher priority than reuse, and can be used to strongly prefer a specific version
-   or variant, without erroring out if it's not possible. Strong preferences are specified
-   as follows:
-
-   .. code-block:: yaml
-
-      packages:
-        foo:
-          prefer:
-          - "@1.1: ~mpi"
-
-4. :ref:`Package requirements <package-requirements>` configured in ``packages.yaml``,
+3. :ref:`Package requirements <package-requirements>` configured in ``packages.yaml``,
    and constraints from the command line as well as ``package.py`` files override all
    of the above. Requirements are specified as follows:
 
@@ -78,8 +66,6 @@ common cases where concretization output may seem surprising at first.
         foo:
           require:
           - "@1.2: +mpi"
-          conflicts:
-          - "@1.4"
 
 Requirements and constraints restrict the set of possible solutions, while reuse
 behavior and preferences influence what an optimal solution looks like.

lib/spack/docs/getting_started.rst

@@ -254,11 +254,12 @@ directory.
 Compiler configuration
 ----------------------
 
-Spack has the ability to build packages with multiple compilers and compiler versions.
-Compilers can be made available to Spack by specifying them manually in ``packages.yaml``,
-or automatically by running ``spack compiler find``.
-For convenience, Spack will automatically detect compilers the first time it needs them,
-if none is available.
+Spack has the ability to build packages with multiple compilers and
+compiler versions. Compilers can be made available to Spack by
+specifying them manually in ``compilers.yaml`` or ``packages.yaml``,
+or automatically by running ``spack compiler find``, but for
+convenience Spack will automatically detect compilers the first time
+it needs them.
 
 .. _cmd-spack-compilers:
 
@@ -273,11 +274,16 @@ compilers`` or ``spack compiler list``:
 
    $ spack compilers
    ==> Available compilers
-   -- gcc ubuntu20.04-x86_64 ---------------------------------------
-   gcc@9.4.0  gcc@8.4.0  gcc@10.5.0
-
-   -- llvm ubuntu20.04-x86_64 --------------------------------------
-   llvm@12.0.0  llvm@11.0.0  llvm@10.0.0
+   -- gcc ---------------------------------------------------------
+       gcc@4.9.0  gcc@4.8.0  gcc@4.7.0  gcc@4.6.2  gcc@4.4.7
+       gcc@4.8.2  gcc@4.7.1  gcc@4.6.3  gcc@4.6.1  gcc@4.1.2
+   -- intel -------------------------------------------------------
+       intel@15.0.0  intel@14.0.0  intel@13.0.0  intel@12.1.0  intel@10.0
+       intel@14.0.3  intel@13.1.1  intel@12.1.5  intel@12.0.4  intel@9.1
+       intel@14.0.2  intel@13.1.0  intel@12.1.3  intel@11.1
+       intel@14.0.1  intel@13.0.1  intel@12.1.2  intel@10.1
+   -- clang -------------------------------------------------------
+       clang@3.4  clang@3.3  clang@3.2  clang@3.1
 
 Any of these compilers can be used to build Spack packages.  More on
 how this is done is in :ref:`sec-specs`.
@@ -296,22 +302,16 @@ An alias for ``spack compiler find``.
 ``spack compiler find``
 ^^^^^^^^^^^^^^^^^^^^^^^
 
-If you do not see a compiler in the list shown by:
+Lists the compilers currently available to Spack. If you do not see
+a compiler in this list, but you want to use it with Spack, you can
+simply run ``spack compiler find`` with the path to where the
+compiler is installed.  For example:
 
 .. code-block:: console
 
-   $ spack compiler list
-
-but you want to use it with Spack, you can simply run ``spack compiler find`` with the
-path to where the compiler is installed.  For example:
-
-.. code-block:: console
-
-   $ spack compiler find /opt/intel/oneapi/compiler/2025.1/bin/
-   ==> Added 1 new compiler to /home/user/.spack/packages.yaml
-       intel-oneapi-compilers@2025.1.0
-   ==> Compilers are defined in the following files:
-       /home/user/.spack/packages.yaml
+   $ spack compiler find /usr/local/tools/ic-13.0.079
+   ==> Added 1 new compiler to ~/.spack/linux/compilers.yaml
+       intel@13.0.079
 
 Or you can run ``spack compiler find`` with no arguments to force
 auto-detection.  This is useful if you do not know where compilers are
@@ -322,7 +322,7 @@ installed, but you know that new compilers have been added to your
 
    $ module load gcc/4.9.0
    $ spack compiler find
-   ==> Added 1 new compiler to /home/user/.spack/packages.yaml
+   ==> Added 1 new compiler to ~/.spack/linux/compilers.yaml
        gcc@4.9.0
 
 This loads the environment module for gcc-4.9.0 to add it to
@@ -331,7 +331,7 @@ This loads the environment module for gcc-4.9.0 to add it to
 .. note::
 
    By default, spack does not fill in the ``modules:`` field in the
-   ``packages.yaml`` file.  If you are using a compiler from a
+   ``compilers.yaml`` file.  If you are using a compiler from a
    module, then you should add this field manually.
    See the section on :ref:`compilers-requiring-modules`.
 
@@ -341,82 +341,91 @@ This loads the environment module for gcc-4.9.0 to add it to
 ``spack compiler info``
 ^^^^^^^^^^^^^^^^^^^^^^^
 
-If you want to see additional information on some specific compilers, you can run ``spack compiler info`` on it:
+If you want to see specifics on a particular compiler, you can run
+``spack compiler info`` on it:
 
 .. code-block:: console
 
-   $ spack compiler info gcc
-   gcc@=8.4.0 languages='c,c++,fortran' arch=linux-ubuntu20.04-x86_64:
-     prefix: /usr
-     compilers:
-       c: /usr/bin/gcc-8
-       cxx: /usr/bin/g++-8
-       fortran: /usr/bin/gfortran-8
+   $ spack compiler info intel@15
+   intel@15.0.0:
+     paths:
+       cc  = /usr/local/bin/icc-15.0.090
+       cxx = /usr/local/bin/icpc-15.0.090
+       f77 = /usr/local/bin/ifort-15.0.090
+       fc  = /usr/local/bin/ifort-15.0.090
+     modules = []
+     operating_system = centos6
+   ...
 
-   gcc@=9.4.0 languages='c,c++,fortran' arch=linux-ubuntu20.04-x86_64:
-     prefix: /usr
-     compilers:
-       c: /usr/bin/gcc
-       cxx: /usr/bin/g++
-       fortran: /usr/bin/gfortran
-
-   gcc@=10.5.0 languages='c,c++,fortran' arch=linux-ubuntu20.04-x86_64:
-     prefix: /usr
-     compilers:
-       c: /usr/bin/gcc-10
-       cxx: /usr/bin/g++-10
-       fortran: /usr/bin/gfortran-10
-
-This shows the details of the compilers that were detected by Spack.
-Notice also that we didn't have to be too specific about the version. We just said ``gcc``, and we got information
-about all the matching compilers.
+This shows which C, C++, and Fortran compilers were detected by Spack.
+Notice also that we didn't have to be too specific about the
+version. We just said ``intel@15``, and information about the only
+matching Intel compiler was displayed.
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Manual compiler configuration
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-If auto-detection fails, you can manually configure a compiler by editing your ``~/.spack/packages.yaml`` file.
-You can do this by running ``spack config edit packages``, which will open the file in
+If auto-detection fails, you can manually configure a compiler by
+editing your ``~/.spack/<platform>/compilers.yaml`` file.  You can do this by running
+``spack config edit compilers``, which will open the file in
 :ref:`your favorite editor <controlling-the-editor>`.
 
-Each compiler has an "external" entry in the file with some ``extra_attributes``:
+Each compiler configuration in the file looks like this:
 
 .. code-block:: yaml
 
-   packages:
-     gcc:
-       externals:
-       - spec: gcc@10.5.0 languages='c,c++,fortran'
-         prefix: /usr
-         extra_attributes:
-           compilers:
-             c: /usr/bin/gcc-10
-             cxx: /usr/bin/g++-10
-             fortran: /usr/bin/gfortran-10
+   compilers:
+   - compiler:
+       modules: []
+       operating_system: centos6
+       paths:
+         cc: /usr/local/bin/icc-15.0.024-beta
+         cxx: /usr/local/bin/icpc-15.0.024-beta
+         f77: /usr/local/bin/ifort-15.0.024-beta
+         fc: /usr/local/bin/ifort-15.0.024-beta
+       spec: intel@15.0.0
 
-The compiler executables are listed under ``extra_attributes:compilers``, and are keyed by language.
-Once you save the file, the configured compilers will show up in the list displayed by ``spack compilers``.
+For compilers that do not support Fortran (like ``clang``), put
+``None`` for ``f77`` and ``fc``:
 
-You can also add compiler flags to manually configured compilers. These flags should be specified in the
-``flags`` section of the compiler specification. The valid flags are ``cflags``, ``cxxflags``, ``fflags``,
+.. code-block:: yaml
+
+   compilers:
+   - compiler:
+       modules: []
+       operating_system: centos6
+       paths:
+         cc: /usr/bin/clang
+         cxx: /usr/bin/clang++
+         f77: None
+         fc: None
+       spec: clang@3.3svn
+
+Once you save the file, the configured compilers will show up in the
+list displayed by ``spack compilers``.
+
+You can also add compiler flags to manually configured compilers. These
+flags should be specified in the ``flags`` section of the compiler
+specification. The valid flags are ``cflags``, ``cxxflags``, ``fflags``,
 ``cppflags``, ``ldflags``, and ``ldlibs``. For example:
 
 .. code-block:: yaml
 
-   packages:
-     gcc:
-       externals:
-       - spec: gcc@10.5.0 languages='c,c++,fortran'
-         prefix: /usr
-         extra_attributes:
-           compilers:
-             c: /usr/bin/gcc-10
-             cxx: /usr/bin/g++-10
-             fortran: /usr/bin/gfortran-10
-           flags:
-             cflags: -O3 -fPIC
-             cxxflags: -O3 -fPIC
-             cppflags: -O3 -fPIC
+   compilers:
+   - compiler:
+       modules: []
+       operating_system: centos6
+       paths:
+         cc: /usr/bin/gcc
+         cxx: /usr/bin/g++
+         f77: /usr/bin/gfortran
+         fc: /usr/bin/gfortran
+       flags:
+         cflags: -O3 -fPIC
+         cxxflags: -O3 -fPIC
+         cppflags: -O3 -fPIC
+       spec: gcc@4.7.2
 
 These flags will be treated by spack as if they were entered from
 the command line each time this compiler is used. The compiler wrappers
@@ -431,44 +440,95 @@ These variables should be specified in the ``environment`` section of the compil
 specification. The operations available to modify the environment are ``set``, ``unset``,
 ``prepend_path``, ``append_path``, and ``remove_path``. For example:
 
+.. code-block:: yaml
+
+   compilers:
+   - compiler:
+       modules: []
+       operating_system: centos6
+       paths:
+         cc: /opt/intel/oneapi/compiler/latest/linux/bin/icx
+         cxx: /opt/intel/oneapi/compiler/latest/linux/bin/icpx
+         f77: /opt/intel/oneapi/compiler/latest/linux/bin/ifx
+         fc: /opt/intel/oneapi/compiler/latest/linux/bin/ifx
+       spec: oneapi@latest
+       environment:
+         set:
+           MKL_ROOT: "/path/to/mkl/root"
+         unset: # A list of environment variables to unset
+           - CC
+         prepend_path: # Similar for append|remove_path
+           LD_LIBRARY_PATH: /ld/paths/added/by/setvars/sh
+
+.. note::
+
+   Spack is in the process of moving compilers from a separate
+   attribute to be handled like all other packages. As part of this
+   process, the ``compilers.yaml`` section will eventually be replaced
+   by configuration in the ``packages.yaml`` section. This new
+   configuration is now available, although it is not yet the default
+   behavior.
+
+Compilers can also be configured as external packages in the
+``packages.yaml`` config file. Any external package for a compiler
+(e.g. ``gcc`` or ``llvm``) will be treated as a configured compiler
+assuming the paths to the compiler executables are determinable from
+the prefix.
+
+If the paths to the compiler executable are not determinable from the
+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:
-     intel-oneapi-compilers:
-       externals:
-       - spec: intel-oneapi-compilers@2025.1.0
-         prefix: /opt/intel/oneapi
+     gcc:
+       external:
+       - spec: gcc@12.2.0 arch=linux-rhel8-skylake
+         prefix: /usr
          extra_attributes:
-           compilers:
-             c: /opt/intel/oneapi/compiler/2025.1/bin/icx
-             cxx: /opt/intel/oneapi/compiler/2025.1/bin/icpx
-             fortran: /opt/intel/oneapi/compiler/2025.1/bin/ifx
            environment:
              set:
-               MKL_ROOT: "/path/to/mkl/root"
-             unset: # A list of environment variables to unset
-               - CC
-             prepend_path: # Similar for append|remove_path
-               LD_LIBRARY_PATH: /ld/paths/added/by/setvars/sh
+               GCC_ROOT: /usr
+       external:
+       - spec: llvm+clang@15.0.0 arch=linux-rhel8-skylake
+         prefix: /usr
+         extra_attributes:
+           compilers:
+             c: /usr/bin/clang-with-suffix
+             cxx: /usr/bin/clang++-with-extra-info
+             fortran: /usr/bin/gfortran
+           extra_rpaths:
+           - /usr/lib/llvm/
 
 ^^^^^^^^^^^^^^^^^^^^^^^
 Build Your Own Compiler
 ^^^^^^^^^^^^^^^^^^^^^^^
 
-If you are particular about which compiler/version you use, you might wish to have Spack build it for you.
-For example:
+If you are particular about which compiler/version you use, you might
+wish to have Spack build it for you.  For example:
 
 .. code-block:: console
 
-   $ spack install gcc@14+binutils
+   $ spack install gcc@4.9.3
 
-Once the compiler is installed, you can start using it without additional configuration:
+Once that has finished, you will need to add it to your
+``compilers.yaml`` file.  You can then set Spack to use it by default
+by adding the following to your ``packages.yaml`` file:
 
-.. code-block:: console
+.. code-block:: yaml
 
-   $ spack install hdf5~mpi %gcc@14
-
-The same holds true for compilers that are made available from buildcaches, when reusing them is allowed.
+   packages:
+     all:
+       compiler: [gcc@4.9.3]
 
 .. _compilers-requiring-modules:
 
@@ -476,26 +536,30 @@ The same holds true for compilers that are made available from buildcaches, when
 Compilers Requiring Modules
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Many installed compilers will work regardless of the environment they are called with.
-However, some installed compilers require environment variables to be set in order to run;
-this is typical for Intel and other proprietary compilers.
+Many installed compilers will work regardless of the environment they
+are called with.  However, some installed compilers require
+``$LD_LIBRARY_PATH`` or other environment variables to be set in order
+to run; this is typical for Intel and other proprietary compilers.
 
-On typical HPC clusters, these environment modifications are usually delegated to some "module" system.
-In such a case, you should tell Spack which module(s) to load in order to run the chosen compiler:
+In such a case, you should tell Spack which module(s) to load in order
+to run the chosen compiler (If the compiler does not come with a
+module file, you might consider making one by hand).  Spack will load
+this module into the environment ONLY when the compiler is run, and
+NOT in general for a package's ``install()`` method.  See, for
+example, this ``compilers.yaml`` file:
 
 .. code-block:: yaml
 
-   packages:
-     gcc:
-       externals:
-       - spec: gcc@10.5.0 languages='c,c++,fortran'
-         prefix: /opt/compilers
-         extra_attributes:
-           compilers:
-             c: /opt/compilers/bin/gcc-10
-             cxx: /opt/compilers/bin/g++-10
-             fortran: /opt/compilers/bin/gfortran-10
-         modules: [gcc/10.5.0]
+   compilers:
+   - compiler:
+       modules: [other/comp/gcc-5.3-sp3]
+       operating_system: SuSE11
+       paths:
+         cc: /usr/local/other/SLES11.3/gcc/5.3.0/bin/gcc
+         cxx: /usr/local/other/SLES11.3/gcc/5.3.0/bin/g++
+         f77: /usr/local/other/SLES11.3/gcc/5.3.0/bin/gfortran
+         fc: /usr/local/other/SLES11.3/gcc/5.3.0/bin/gfortran
+       spec: gcc@5.3.0
 
 Some compilers require special environment settings to be loaded not just
 to run, but also to execute the code they build, breaking packages that
@@ -516,7 +580,7 @@ Licensed Compilers
 ^^^^^^^^^^^^^^^^^^
 
 Some proprietary compilers require licensing to use.  If you need to
-use a licensed compiler, the process is similar to a mix of
+use a licensed compiler (eg, PGI), the process is similar to a mix of
 build your own, plus modules:
 
 #. Create a Spack package (if it doesn't exist already) to install
@@ -526,21 +590,24 @@ build your own, plus modules:
    using Spack to load the module it just created, and running simple
    builds (eg: ``cc helloWorld.c && ./a.out``)
 
-#. Add the newly-installed compiler to ``packages.yaml`` as shown above.
+#. Add the newly-installed compiler to ``compilers.yaml`` as shown
+   above.
 
 .. _mixed-toolchains:
 
-^^^^^^^^^^^^^^^^^^^^^^^^^^
-Fortran compilers on macOS
-^^^^^^^^^^^^^^^^^^^^^^^^^^
+^^^^^^^^^^^^^^^^
+Mixed Toolchains
+^^^^^^^^^^^^^^^^
 
 Modern compilers typically come with related compilers for C, C++ and
 Fortran bundled together.  When possible, results are best if the same
 compiler is used for all languages.
 
-In some cases, this is not possible.  For example, XCode on macOS provides no Fortran compilers.
-The user is therefore forced to use a mixed toolchain: XCode-provided Clang for C/C++ and e.g.
-GNU ``gfortran`` for Fortran.
+In some cases, this is not possible.  For example, starting with macOS El
+Capitan (10.11), many packages no longer build with GCC, but XCode
+provides no Fortran compilers.  The user is therefore forced to use a
+mixed toolchain: XCode-provided Clang for C/C++ and GNU ``gfortran`` for
+Fortran.
 
 #. You need to make sure that Xcode is installed. Run the following command:
 
@@ -593,25 +660,45 @@ GNU ``gfortran`` for Fortran.
 
    Note: the flag is ``-license``, not ``--license``.
 
+#. Run ``spack compiler find`` to locate Clang.
+
 #. There are different ways to get ``gfortran`` on macOS. For example, you can
    install GCC with Spack (``spack install gcc``), with Homebrew (``brew install
    gcc``), or from a `DMG installer
    <https://github.com/fxcoudert/gfortran-for-macOS/releases>`_.
 
-#. Run ``spack compiler find`` to locate both Apple-Clang and GCC.
+#. The only thing left to do is to edit ``~/.spack/darwin/compilers.yaml`` to provide
+   the path to ``gfortran``:
 
-Since languages in Spack are modeled as virtual packages, ``apple-clang`` will be used to provide
-C and C++, while GCC will be used for Fortran.
+   .. code-block:: yaml
+
+      compilers:
+      - compiler:
+        # ...
+        paths:
+          cc: /usr/bin/clang
+          cxx: /usr/bin/clang++
+          f77: /path/to/bin/gfortran
+          fc: /path/to/bin/gfortran
+        spec: apple-clang@11.0.0
+
+
+   If you used Spack to install GCC, you can get the installation prefix by
+   ``spack location -i gcc`` (this will only work if you have a single version
+   of GCC installed). Whereas for Homebrew, GCC is installed in
+   ``/usr/local/Cellar/gcc/x.y.z``. With the DMG installer, the correct path
+   will be ``/usr/local/gfortran``.
 
 ^^^^^^^^^^^^^^^^^^^^^
 Compiler Verification
 ^^^^^^^^^^^^^^^^^^^^^
 
-You can verify that your compilers are configured properly by installing a simple package. For example:
+You can verify that your compilers are configured properly by installing a
+simple package.  For example:
 
 .. code-block:: console
 
-   $ spack install zlib-ng%gcc@5.3.0
+   $ spack install zlib%gcc@5.3.0
 
 
 .. _vendor-specific-compiler-configuration:
@@ -620,7 +707,9 @@ You can verify that your compilers are configured properly by installing a simpl
 Vendor-Specific Compiler Configuration
 --------------------------------------
 
-This section provides details on how to get vendor-specific compilers working.
+With Spack, things usually "just work" with GCC.  Not so for other
+compilers.  This section provides details on how to get specific
+compilers working.
 
 ^^^^^^^^^^^^^^^
 Intel Compilers
@@ -642,8 +731,8 @@ compilers:
       you have installed from the ``PATH`` environment variable.
 
       If you want use a version of ``gcc`` or ``g++`` other than the default
-      version on your system, you need to use either the ``--gcc-install-dir``
-      or ``--gcc-toolchain`` compiler option to specify the path to the version of
+      version on your system, you need to use either the ``-gcc-name``
+      or ``-gxx-name`` compiler option to specify the path to the version of
       ``gcc`` or ``g++`` that you want to use."
 
       -- `Intel Reference Guide <https://software.intel.com/en-us/node/522750>`_
@@ -651,12 +740,76 @@ compilers:
 Intel compilers may therefore be configured in one of two ways with
 Spack: using modules, or using compiler flags.
 
+""""""""""""""""""""""""""
+Configuration with Modules
+""""""""""""""""""""""""""
+
+One can control which GCC is seen by the Intel compiler with modules.
+A module must be loaded both for the Intel Compiler (so it will run)
+and GCC (so the compiler can find the intended GCC).  The following
+configuration in ``compilers.yaml`` illustrates this technique:
+
+.. code-block:: yaml
+
+   compilers:
+   - compiler:
+       modules: [gcc-4.9.3, intel-15.0.24]
+       operating_system: centos7
+       paths:
+         cc: /opt/intel-15.0.24/bin/icc-15.0.24-beta
+         cxx: /opt/intel-15.0.24/bin/icpc-15.0.24-beta
+         f77: /opt/intel-15.0.24/bin/ifort-15.0.24-beta
+         fc: /opt/intel-15.0.24/bin/ifort-15.0.24-beta
+       spec: intel@15.0.24.4.9.3
+
+
+.. note::
+
+   The version number on the Intel compiler is a combination of
+   the "native" Intel version number and the GNU compiler it is
+   targeting.
+
+""""""""""""""""""""""""""
+Command Line Configuration
+""""""""""""""""""""""""""
+
+One can also control which GCC is seen by the Intel compiler by adding
+flags to the ``icc`` command:
+
+#. Identify the location of the compiler you just installed:
+
+   .. code-block:: console
+
+       $ spack location --install-dir gcc
+       ~/spack/opt/spack/linux-centos7-x86_64/gcc-4.9.3-iy4rw...
+
+#. Set up ``compilers.yaml``, for example:
+
+   .. code-block:: yaml
+
+       compilers:
+       - compiler:
+           modules: [intel-15.0.24]
+           operating_system: centos7
+           paths:
+             cc: /opt/intel-15.0.24/bin/icc-15.0.24-beta
+             cxx: /opt/intel-15.0.24/bin/icpc-15.0.24-beta
+             f77: /opt/intel-15.0.24/bin/ifort-15.0.24-beta
+             fc: /opt/intel-15.0.24/bin/ifort-15.0.24-beta
+           flags:
+             cflags: -gcc-name ~/spack/opt/spack/linux-centos7-x86_64/gcc-4.9.3-iy4rw.../bin/gcc
+             cxxflags: -gxx-name ~/spack/opt/spack/linux-centos7-x86_64/gcc-4.9.3-iy4rw.../bin/g++
+             fflags: -gcc-name ~/spack/opt/spack/linux-centos7-x86_64/gcc-4.9.3-iy4rw.../bin/gcc
+           spec: intel@15.0.24.4.9.3
+
+
 ^^^
 NAG
 ^^^
 
-The Numerical Algorithms Group provides a licensed Fortran compiler.
-It is recommended to use GCC for your C/C++ compilers.
+The Numerical Algorithms Group provides a licensed Fortran compiler. Like Clang,
+this requires you to set up a :ref:`mixed-toolchains`. It is recommended to use
+GCC for your C/C++ compilers.
 
 The NAG Fortran compilers are a bit more strict than other compilers, and many
 packages will fail to install with error messages like:
@@ -673,40 +826,44 @@ the command line:
 
    $ spack install openmpi fflags="-mismatch"
 
-Or it can be set permanently in your ``packages.yaml``:
+Or it can be set permanently in your ``compilers.yaml``:
 
 .. code-block:: yaml
 
-   packages:
-     nag:
-       externals:
-       - spec: nag@6.1
-         prefix: /opt/nag/bin
-         extra_attributes:
-           compilers:
-             fortran: /opt/nag/bin/nagfor
-         flags:
-           fflags: -mismatch
+   - compiler:
+    modules: []
+    operating_system: centos6
+    paths:
+      cc: /soft/spack/opt/spack/linux-x86_64/gcc-5.3.0/gcc-6.1.0-q2zosj3igepi3pjnqt74bwazmptr5gpj/bin/gcc
+      cxx: /soft/spack/opt/spack/linux-x86_64/gcc-5.3.0/gcc-6.1.0-q2zosj3igepi3pjnqt74bwazmptr5gpj/bin/g++
+      f77: /soft/spack/opt/spack/linux-x86_64/gcc-4.4.7/nag-6.1-jt3h5hwt5myezgqguhfsan52zcskqene/bin/nagfor
+      fc: /soft/spack/opt/spack/linux-x86_64/gcc-4.4.7/nag-6.1-jt3h5hwt5myezgqguhfsan52zcskqene/bin/nagfor
+    flags:
+      fflags: -mismatch
+    spec: nag@6.1
+
 
 ---------------
 System Packages
 ---------------
 
-Once compilers are configured, one needs to determine which pre-installed system packages,
-if any, to use in builds.  These are also configured in the ``~/.spack/packages.yaml`` file.
-For example, to use an OpenMPI installed in /opt/local, one would use:
+Once compilers are configured, one needs to determine which
+pre-installed system packages, if any, to use in builds.  This is
+configured in the file ``~/.spack/packages.yaml``.  For example, to use
+an OpenMPI installed in /opt/local, one would use:
 
 .. code-block:: yaml
 
-   packages:
-     openmpi:
-       buildable: False
-       externals:
-       - spec: openmpi@1.10.1
-         prefix: /opt/local
+    packages:
+        openmpi:
+            externals:
+            - spec: openmpi@1.10.1
+              prefix: /opt/local
+            buildable: False
 
-In general, *Spack is easier to use and more reliable if it builds all of its own dependencies*.
-However, there are several packages for which one commonly needs to use system versions:
+In general, Spack is easier to use and more reliable if it builds all of
+its own dependencies.  However, there are several packages for which one
+commonly needs to use system versions:
 
 ^^^
 MPI
@@ -719,7 +876,8 @@ you are unlikely to get a working MPI from Spack.  Instead, use an
 appropriate pre-installed MPI.
 
 If you choose a pre-installed MPI, you should consider using the
-pre-installed compiler used to build that MPI.
+pre-installed compiler used to build that MPI; see above on
+``compilers.yaml``.
 
 ^^^^^^^
 OpenSSL
@@ -1283,9 +1441,9 @@ To configure Spack, first run the following command inside the Spack console:
    spack compiler find
 
 This creates a ``.staging`` directory in our Spack prefix, along with a ``windows`` subdirectory
-containing a ``packages.yaml`` file. On a fresh Windows install with the above packages
+containing a ``compilers.yaml`` file. On a fresh Windows install with the above packages
 installed, this command should only detect Microsoft Visual Studio and the Intel Fortran
-compiler will be integrated within the first version of MSVC present in the ``packages.yaml``
+compiler will be integrated within the first version of MSVC present in the ``compilers.yaml``
 output.
 
 Spack provides a default ``config.yaml`` file for Windows that it will use unless overridden.

lib/spack/docs/gpu_configuration.rst

@@ -23,6 +23,7 @@ components for use by dependent packages:
 
    packages:
      all:
+       compiler: [rocmcc@=5.3.0]
        variants: amdgpu_target=gfx90a
      hip:
        buildable: false
@@ -69,15 +70,16 @@ This is in combination with the following compiler definition:
 
 .. code-block:: yaml
 
-   packages:
-     llvm-amdgpu:
-       externals:
-       - spec: llvm-amdgpu@=5.3.0
-         prefix: /opt/rocm-5.3.0
-         compilers:
-           c: /opt/rocm-5.3.0/bin/amdclang
-           cxx: /opt/rocm-5.3.0/bin/amdclang++
-           fortran: null
+   compilers:
+   - compiler:
+       spec: rocmcc@=5.3.0
+       paths:
+         cc: /opt/rocm-5.3.0/bin/amdclang
+         cxx: /opt/rocm-5.3.0/bin/amdclang++
+         f77: null
+         fc: /opt/rocm-5.3.0/bin/amdflang
+       operating_system: rhel8
+       target: x86_64
 
 This includes the following considerations:
 

lib/spack/docs/include_yaml.rst

@@ -1,65 +0,0 @@
-.. Copyright Spack Project Developers. See COPYRIGHT file for details.
-
-   SPDX-License-Identifier: (Apache-2.0 OR MIT)
-
-.. _include-yaml:
-
-===============================
-Include Settings (include.yaml)
-===============================
-
-Spack allows you to include configuration files through ``include.yaml``.
-Using the ``include:`` heading results in pulling in external configuration
-information to be used by any Spack command.
-
-Included configuration files are required *unless* they are explicitly optional
-or the entry's condition evaluates to ``false``. Optional includes are specified
-with the ``optional`` clause and conditional with the ``when`` clause. For
-example,
-
-.. code-block:: yaml
-
-   include:
-   - /path/to/a/required/config.yaml
-   - path: /path/to/$os/$target/config
-     optional: true
-   - path: /path/to/os-specific/config-dir
-     when: os == "ventura"
-
-shows all three. The first entry, ``/path/to/a/required/config.yaml``,
-indicates that included ``config.yaml`` file is required (so must exist).
-Use of ``optional: true`` for ``/path/to/$os/$target/config`` means
-the path is only included if it exists. The condition ``os == "ventura"``
-in the ``when`` clause for ``/path/to/os-specific/config-dir`` means the
-path is only included when the operating system (``os``) is ``ventura``.
-
-The same conditions and variables in `Spec List References 
-<https://spack.readthedocs.io/en/latest/environments.html#spec-list-references>`_
-can be used for conditional activation in the ``when`` clauses.
-
-Included files can be specified by path or by their parent directory.
-Paths may be absolute, relative (to the configuration file including the path), 
-or specified as URLs. Only the ``file``, ``ftp``, ``http`` and ``https`` protocols (or
-schemes) are supported. Spack-specific, environment and user path variables
-can be used. (See :ref:`config-file-variables` for more information.)
-
-A ``sha256`` is required for remote file URLs and must be specified as follows:
-
-.. code-block:: yaml
-
-   include:
-   - path: https://github.com/path/to/raw/config/compilers.yaml
-     sha256: 26e871804a92cd07bb3d611b31b4156ae93d35b6a6d6e0ef3a67871fcb1d258b
-
-Additionally, remote file URLs must link to the **raw** form of the file's
-contents (e.g., `GitHub
-<https://docs.github.com/en/repositories/working-with-files/using-files/viewing-and-understanding-files#viewing-or-copying-the-raw-file-content>`_
-or `GitLab
-<https://docs.gitlab.com/ee/api/repository_files.html#get-raw-file-from-repository>`_).
-
-.. warning::
-
-   Recursive includes are not currently processed in a breadth-first manner
-   so the value of a configuration option that is altered by multiple included
-   files may not be what you expect. This will be addressed in a future
-   update.

lib/spack/docs/index.rst

@@ -71,11 +71,9 @@ or refer to the full manual below.
 
    configuration
    config_yaml
-   include_yaml
    packages_yaml
    build_settings
    environments
-   env_vars_yaml
    containers
    mirrors
    module_file_support

lib/spack/docs/module_file_support.rst

@@ -128,7 +128,7 @@ depend on the spec:
 
 .. code-block:: python
 
-   def setup_run_environment(self, env: EnvironmentModifications) -> None:
+   def setup_run_environment(self, env):
        if self.spec.satisfies("+foo"):
            env.set("FOO", "bar")
 
@@ -142,7 +142,7 @@ For example, a simplified version of the ``python`` package could look like this
 
 .. code-block:: python
 
-   def setup_dependent_run_environment(self, env: EnvironmentModifications, dependent_spec: Spec) -> None:
+   def setup_dependent_run_environment(self, env, dependent_spec):
        if dependent_spec.package.extends(self.spec):
            env.prepend_path("PYTHONPATH", dependent_spec.prefix.lib.python)
 

lib/spack/docs/packages_yaml.rst

@@ -486,8 +486,6 @@ present. For instance with a configuration like:
 
 you will use ``mvapich2~cuda %gcc`` as an ``mpi`` provider.
 
-.. _package-strong-preferences:
-
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Conflicts and strong preferences
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -557,13 +555,14 @@ preferences.
    FAQ: :ref:`Why does Spack pick particular versions and variants? <faq-concretizer-precedence>`
 
 
-The ``target`` and ``providers`` preferences
+Most package preferences (``compilers``, ``target`` and ``providers``)
 can only be set globally under the ``all`` section of ``packages.yaml``:
 
 .. code-block:: yaml
 
    packages:
      all:
+       compiler: [gcc@12.2.0, clang@12:, oneapi@2023:]
        target: [x86_64_v3]
        providers:
          mpi: [mvapich2, mpich, openmpi]

lib/spack/docs/packaging_guide.rst

@@ -369,9 +369,9 @@ If you have a collection of software expected to work well together with
 no source code of its own, you can create a :ref:`BundlePackage <bundlepackage>`.
 Examples where bundle packages can be useful include defining suites of
 applications (e.g, `EcpProxyApps
-<https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/ecp_proxy_apps/package.py>`_), commonly used libraries
-(e.g., `AmdAocl <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/amd_aocl/package.py>`_),
-and software development kits (e.g., `EcpDataVisSdk <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/ecp_data_vis_sdk/package.py>`_).
+<https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/ecp-proxy-apps/package.py>`_), commonly used libraries
+(e.g., `AmdAocl <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/amd-aocl/package.py>`_),
+and software development kits (e.g., `EcpDataVisSdk <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/ecp-data-vis-sdk/package.py>`_).
 
 These versioned packages primarily consist of dependencies on the associated
 software packages. They can include :ref:`variants <variants>` to ensure
@@ -443,7 +443,7 @@ lives in:
 .. code-block:: console
 
    $ spack location -p gmp
-   ${SPACK_ROOT}/var/spack/repos/spack_repo/builtin/packages/gmp/package.py
+   ${SPACK_ROOT}/var/spack/repos/builtin/packages/gmp/package.py
 
 but ``spack edit`` provides a much simpler shortcut and saves you the
 trouble of typing the full path.
@@ -457,19 +457,19 @@ live in Spack's directory structure.  In general, :ref:`cmd-spack-create`
 handles creating package files for you, so you can skip most of the
 details here.
 
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-``var/spack/repos/spack_repo/builtin/packages``
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+``var/spack/repos/builtin/packages``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 A Spack installation directory is structured like a standard UNIX
 install prefix (``bin``, ``lib``, ``include``, ``var``, ``opt``,
 etc.).  Most of the code for Spack lives in ``$SPACK_ROOT/lib/spack``.
-Packages themselves live in ``$SPACK_ROOT/var/spack/repos/spack_repo/builtin/packages``.
+Packages themselves live in ``$SPACK_ROOT/var/spack/repos/builtin/packages``.
 
 If you ``cd`` to that directory, you will see directories for each
 package:
 
-.. command-output:: cd $SPACK_ROOT/var/spack/repos/spack_repo/builtin/packages && ls
+.. command-output:: cd $SPACK_ROOT/var/spack/repos/builtin/packages && ls
    :shell:
    :ellipsis: 10
 
@@ -479,7 +479,7 @@ package lives in:
 
 .. code-block:: none
 
-   $SPACK_ROOT/var/spack/repos/spack_repo/builtin/packages/libelf/package.py
+   $SPACK_ROOT/var/spack/repos/builtin/packages/libelf/package.py
 
 Alongside the ``package.py`` file, a package may contain extra
 directories or files (like patches) that it needs to build.
@@ -492,7 +492,7 @@ Packages are named after the directory containing ``package.py``. So,
 ``libelf``'s ``package.py`` lives in a directory called ``libelf``.
 The ``package.py`` file defines a class called ``Libelf``, which
 extends Spack's ``Package`` class.  For example, here is
-``$SPACK_ROOT/var/spack/repos/spack_repo/builtin/packages/libelf/package.py``:
+``$SPACK_ROOT/var/spack/repos/builtin/packages/libelf/package.py``:
 
 .. code-block:: python
    :linenos:
@@ -520,7 +520,7 @@ these:
    $ spack install libelf@0.8.13
 
 Spack sees the package name in the spec and looks for
-``libelf/package.py`` in ``var/spack/repos/spack_repo/builtin/packages``.
+``libelf/package.py`` in ``var/spack/repos/builtin/packages``.
 Likewise, if you run ``spack install py-numpy``, Spack looks for
 ``py-numpy/package.py``.
 
@@ -686,7 +686,7 @@ https://www.open-mpi.org/software/ompi/v2.1/downloads/openmpi-2.1.1.tar.bz2
 In order to handle this, you can define a ``url_for_version()`` function
 like so:
 
-.. literalinclude:: _spack_root/var/spack/repos/spack_repo/builtin/packages/openmpi/package.py
+.. literalinclude:: _spack_root/var/spack/repos/builtin/packages/openmpi/package.py
    :pyobject: Openmpi.url_for_version
 
 With the use of this ``url_for_version()``, Spack knows to download OpenMPI ``2.1.1``
@@ -787,7 +787,7 @@ of GNU. For that, Spack goes a step further and defines a mixin class that
 takes care of all of the plumbing and requires packagers to just define a proper
 ``gnu_mirror_path`` attribute:
 
-.. literalinclude:: _spack_root/var/spack/repos/spack_repo/builtin/packages/autoconf/package.py
+.. literalinclude:: _spack_root/var/spack/repos/builtin/packages/autoconf/package.py
    :lines: 9-18
 
 ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -1995,7 +1995,7 @@ structure like this:
 
 .. code-block:: none
 
-   $SPACK_ROOT/var/spack/repos/spack_repo/builtin/packages/
+   $SPACK_ROOT/var/spack/repos/builtin/packages/
        mvapich2/
            package.py
            ad_lustre_rwcontig_open_source.patch
@@ -2133,7 +2133,7 @@ handles ``RPATH``:
 
 .. _pyside-patch:
 
-.. literalinclude:: _spack_root/var/spack/repos/spack_repo/builtin/packages/py_pyside/package.py
+.. literalinclude:: _spack_root/var/spack/repos/builtin/packages/py-pyside/package.py
    :pyobject: PyPyside.patch
    :linenos:
 
@@ -2201,7 +2201,7 @@ using the ``spack resource show`` command::
 
   $ spack resource show 3877ab54
   3877ab548f88597ab2327a2230ee048d2d07ace1062efe81fc92e91b7f39cd00
-      path:       /home/spackuser/src/spack/var/spack/repos/spack_repo/builtin/packages/m4/gnulib-pgi.patch
+      path:       /home/spackuser/src/spack/var/spack/repos/builtin/packages/m4/gnulib-pgi.patch
       applies to: builtin.m4
 
 ``spack resource show`` looks up downloadable resources from package
@@ -2219,7 +2219,7 @@ wonder where the extra boost patches are coming from::
           ^boost@1.68.0%apple-clang@9.0.0+atomic+chrono~clanglibcpp cxxstd=default +date_time~debug+exception+filesystem+graph~icu+iostreams+locale+log+math~mpi+multithreaded~numpy patches=2ab6c72d03dec6a4ae20220a9dfd5c8c572c5294252155b85c6874d97c323199,b37164268f34f7133cbc9a4066ae98fda08adf51e1172223f6a969909216870f ~pic+program_options~python+random+regex+serialization+shared+signals~singlethreaded+system~taggedlayout+test+thread+timer~versionedlayout+wave arch=darwin-highsierra-x86_64
   $ spack resource show b37164268
   b37164268f34f7133cbc9a4066ae98fda08adf51e1172223f6a969909216870f
-      path:       /home/spackuser/src/spack/var/spack/repos/spack_repo/builtin/packages/dealii/boost_1.68.0.patch
+      path:       /home/spackuser/src/spack/var/spack/repos/builtin/packages/dealii/boost_1.68.0.patch
       applies to: builtin.boost
       patched by: builtin.dealii
 
@@ -2930,7 +2930,7 @@ this, Spack provides four different methods that can be overridden in a package:
 
 The Qt package, for instance, uses this call:
 
-.. literalinclude:: _spack_root/var/spack/repos/spack_repo/builtin/packages/qt/package.py
+.. literalinclude:: _spack_root/var/spack/repos/builtin/packages/qt/package.py
    :pyobject: Qt.setup_dependent_build_environment
    :linenos:
 
@@ -2958,7 +2958,7 @@ variables to be used by the dependent. This is done by implementing
 :meth:`setup_dependent_package <spack.package_base.PackageBase.setup_dependent_package>`. An
 example of this can be found in the ``Python`` package:
 
-.. literalinclude:: _spack_root/var/spack/repos/spack_repo/builtin/packages/python/package.py
+.. literalinclude:: _spack_root/var/spack/repos/builtin/packages/python/package.py
    :pyobject: Python.setup_dependent_package
    :linenos:
 
@@ -3785,7 +3785,7 @@ It is usually sufficient for a packager to override a few
 build system specific helper methods or attributes to provide, for instance,
 configure arguments:
 
-.. literalinclude::  _spack_root/var/spack/repos/spack_repo/builtin/packages/m4/package.py
+.. literalinclude::  _spack_root/var/spack/repos/builtin/packages/m4/package.py
     :pyobject: M4.configure_args
     :linenos:
 
@@ -4110,7 +4110,7 @@ Shell command functions
 
 Recall the install method from ``libelf``:
 
-.. literalinclude::  _spack_root/var/spack/repos/spack_repo/builtin/packages/libelf/package.py
+.. literalinclude::  _spack_root/var/spack/repos/builtin/packages/libelf/package.py
    :pyobject: Libelf.install
    :linenos:
 
@@ -4901,7 +4901,7 @@ the one passed to install, only the MPI implementations all set some
 additional properties on it to help you out.  E.g., in openmpi, you'll
 find this:
 
-.. literalinclude:: _spack_root/var/spack/repos/spack_repo/builtin/packages/openmpi/package.py
+.. literalinclude:: _spack_root/var/spack/repos/builtin/packages/openmpi/package.py
    :pyobject: Openmpi.setup_dependent_package
 
 That code allows the ``openmpi`` package to associate an ``mpicc`` property
@@ -6001,16 +6001,16 @@ with those implemented in the package itself.
    * - Parent/Provider Package
      - Stand-alone Tests
    * - `C
-       <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/c>`_
+       <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/c>`_
      - Compiles ``hello.c`` and runs it
    * - `Cxx
-       <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/cxx>`_
+       <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/cxx>`_
      - Compiles and runs several ``hello`` programs
    * - `Fortran
-       <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/fortran>`_
+       <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/fortran>`_
      - Compiles and runs ``hello`` programs (``F`` and ``f90``)
    * - `Mpi
-       <https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/mpi>`_
+       <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/mpi>`_
      - Compiles and runs ``mpi_hello`` (``c``, ``fortran``)
    * - :ref:`PythonPackage <pythonpackage>`
      - Imports modules listed in the ``self.import_modules`` property with defaults derived from the tarball
@@ -6031,7 +6031,7 @@ maintainers provide additional stand-alone tests customized to the package.
 One example of a package that adds its own stand-alone tests to those
 "inherited" by the virtual package it provides an implementation for is
 the `Openmpi package
-<https://github.com/spack/spack/blob/develop/var/spack/repos/spack_repo/builtin/packages/openmpi/package.py>`_.
+<https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/openmpi/package.py>`_.
 
 Below are snippets from running and viewing the stand-alone test results
 for ``openmpi``:

lib/spack/docs/pipelines.rst

@@ -330,7 +330,7 @@ that ``--tests`` is passed to ``spack ci rebuild`` as part of the
           - spack --version
           - cd ${SPACK_CONCRETE_ENV_DIR}
           - spack env activate --without-view .
-          - spack config add "config:install_tree:projections:${SPACK_JOB_SPEC_PKG_NAME}:'morepadding/{architecture.platform}-{architecture.target}/{name}-{version}-{hash}'"
+          - spack config add "config:install_tree:projections:${SPACK_JOB_SPEC_PKG_NAME}:'morepadding/{architecture}/{compiler.name}-{compiler.version}/{name}-{version}-{hash}'"
            - mkdir -p ${SPACK_ARTIFACTS_ROOT}/user_data
            - if [[ -r /mnt/key/intermediate_ci_signing_key.gpg ]]; then spack gpg trust /mnt/key/intermediate_ci_signing_key.gpg; fi
            - if [[ -r /mnt/key/spack_public_key.gpg ]]; then spack gpg trust /mnt/key/spack_public_key.gpg; fi
@@ -820,69 +820,6 @@ presence of a ``SPACK_CDASH_AUTH_TOKEN`` environment variable during the
 build group on CDash called "Release Testing" (that group will be created if
 it didn't already exist).
 
-.. _ci_artifacts:
-
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-CI Artifacts Directory Layout
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-When running the CI build using the command ``spack ci rebuild`` a number of directories are created for
-storing data generated during the CI job. The default root directory for artifacts is ``job_scratch_root``.
-This can be overridden by passing the argument ``--artifacts-root`` to the ``spack ci generate`` command
-or by setting the ``SPACK_ARTIFACTS_ROOT`` environment variable in the build job scripts.
-
-The top level directories under the artifact root are ``concrete_environment``, ``logs``, ``reproduction``,
-``tests``, and ``user_data``. Spack does not restrict what is written to any of these directories nor does
-it require user specified files be written to any specific directory.
-
-------------------------
-``concrete_environment``
-------------------------
-
-The directory ``concrete_environment`` is used to communicate the ci generate processed ``spack.yaml`` and
-the concrete ``spack.lock`` for the CI environment.
-
---------
-``logs``
---------
-
-The directory ``logs`` contains the spack build log, ``spack-build-out.txt``, and the spack build environment
-modification file, ``spack-build-mod-env.txt``. Additionally all files specified by the packages ``Builder``
-property ``archive_files`` are also copied here (ie. ``CMakeCache.txt`` in ``CMakeBuilder``).
-
-----------------
-``reproduction``
-----------------
-
-The directory ``reproduction`` is used to store the files needed by the ``spack reproduce-build`` command.
-This includes ``repro.json``, copies of all of the files in ``concrete_environment``, the concrete spec
-JSON file for the current spec being built, and all of the files written in the artifacts root directory.
-
-The ``repro.json`` file is not versioned and is only designed to work with the version of spack CI was run with.
-An example of what a ``repro.json`` may look like is here.
-
-.. code:: json
-
-  {
-    "job_name": "adios2@2.9.2 /feaevuj %gcc@11.4.0 arch=linux-ubuntu20.04-x86_64_v3 E4S ROCm External",
-    "job_spec_json": "adios2.json",
-    "ci_project_dir": "/builds/spack/spack"
-  }
-
----------
-``tests``
----------
-
-The directory ``tests`` is used to store output from running ``spack test <job spec>``. This may or may not have
-data in it depending on the package that was built and the availability of tests.
-
--------------
-``user_data``
--------------
-
-The directory ``user_data`` is used to store everything else that shouldn't be copied to the ``reproduction`` direcotory.
-Users may use this to store additional logs or metrics or other types of files generated by the build job.
-
 -------------------------------------
 Using a custom spack in your pipeline
 -------------------------------------

lib/spack/docs/repositories.rst

@@ -9,7 +9,7 @@ Package Repositories (repos.yaml)
 =================================
 
 Spack comes with thousands of built-in package recipes in
-``var/spack/repos/spack_repo/builtin/``.  This is a **package repository** -- a
+``var/spack/repos/builtin/``.  This is a **package repository** -- a
 directory that Spack searches when it needs to find a package by name.
 You may need to maintain packages for restricted, proprietary or
 experimental software separately from the built-in repository. Spack
@@ -69,7 +69,7 @@ The default ``etc/spack/defaults/repos.yaml`` file looks like this:
 .. code-block:: yaml
 
   repos:
-  - $spack/var/spack/repos/spack_repo/builtin
+  - $spack/var/spack/repos/builtin
 
 The file starts with ``repos:`` and contains a single ordered list of
 paths to repositories. Each path is on a separate line starting with
@@ -78,16 +78,16 @@ paths to repositories. Each path is on a separate line starting with
 .. code-block:: yaml
 
   repos:
-  - /opt/repos/spack_repo/local_repo
-  - $spack/var/spack/repos/spack_repo/builtin
+  - /opt/local-repo
+  - $spack/var/spack/repos/builtin
 
 When Spack interprets a spec, e.g., ``mpich`` in ``spack install mpich``,
 it searches these repositories in order (first to last) to resolve each
 package name.  In this example, Spack will look for the following
 packages and use the first valid file:
 
-1. ``/opt/repos/spack_repo/local_repo/packages/mpich/package.py``
-2. ``$spack/var/spack/repos/spack_repo/builtin/packages/mpich/package.py``
+1. ``/opt/local-repo/packages/mpich/package.py``
+2. ``$spack/var/spack/repos/builtin/packages/mpich/package.py``
 
 .. note::
 
@@ -101,15 +101,14 @@ Namespaces
 
 Every repository in Spack has an associated **namespace** defined in its
 top-level ``repo.yaml`` file.  If you look at
-``var/spack/repos/spack_repo/builtin/repo.yaml`` in the built-in repository, you'll
+``var/spack/repos/builtin/repo.yaml`` in the built-in repository, you'll
 see that its namespace is ``builtin``:
 
 .. code-block:: console
 
-  $ cat var/spack/repos/spack_repo/builtin/repo.yaml
+  $ cat var/spack/repos/builtin/repo.yaml
   repo:
     namespace: builtin
-    api: v2.0
 
 Spack records the repository namespace of each installed package.  For
 example, if you install the ``mpich`` package from the ``builtin`` repo,
@@ -218,15 +217,15 @@ Suppose you have three repositories: the builtin Spack repo
 repo containing your own prototype packages (``proto``).  Suppose they
 contain packages as follows:
 
-  +--------------+-----------------------------------------------+-----------------------------+
-  | Namespace    | Path to repo                                  | Packages                    |
-  +==============+===============================================+=============================+
-  | ``proto``    | ``~/my_spack_repos/spack_repo/proto``         | ``mpich``                   |
-  +--------------+-----------------------------------------------+-----------------------------+
-  | ``llnl``     | ``/usr/local/repos/spack_repo/llnl``          | ``hdf5``                    |
-  +--------------+-----------------------------------------------+-----------------------------+
-  | ``builtin``  | ``$spack/var/spack/repos/spack_repo/builtin`` | ``mpich``, ``hdf5``, others |
-  +--------------+-----------------------------------------------+-----------------------------+
+  +--------------+------------------------------------+-----------------------------+
+  | Namespace    | Path to repo                       | Packages                    |
+  +==============+====================================+=============================+
+  | ``proto``    | ``~/proto``                        | ``mpich``                   |
+  +--------------+------------------------------------+-----------------------------+
+  | ``llnl``     | ``/usr/local/llnl``                | ``hdf5``                    |
+  +--------------+------------------------------------+-----------------------------+
+  | ``builtin``  | ``$spack/var/spack/repos/builtin`` | ``mpich``, ``hdf5``, others |
+  +--------------+------------------------------------+-----------------------------+
 
 Suppose that ``hdf5`` depends on ``mpich``.  You can override the
 built-in ``hdf5`` by adding the ``llnl`` repo to ``repos.yaml``:
@@ -234,8 +233,8 @@ built-in ``hdf5`` by adding the ``llnl`` repo to ``repos.yaml``:
 .. code-block:: yaml
 
    repos:
-   - /usr/local/repos/spack_repo/llnl
-   - $spack/var/spack/repos/spack_repo/builtin
+   - /usr/local/llnl
+   - $spack/var/spack/repos/builtin
 
 ``spack install hdf5`` will install ``llnl.hdf5 ^builtin.mpich``.
 
@@ -244,9 +243,9 @@ If, instead, ``repos.yaml`` looks like this:
 .. code-block:: yaml
 
    repos:
-   - ~/my_spack_repos/spack_repo/proto
-   - /usr/local/repos/spack_repo/llnl
-   - $spack/var/spack/repos/spack_repo/builtin
+   - ~/proto
+   - /usr/local/llnl
+   - $spack/var/spack/repos/builtin
 
 ``spack install hdf5`` will install ``llnl.hdf5 ^proto.mpich``.
 
@@ -327,8 +326,8 @@ files, use ``spack repo list``.
 
   $ spack repo list
   ==> 2 package repositories.
-  myrepo     v2.0    ~/my_spack_repos/spack_repo/myrepo
-  builtin    v2.0    ~/spack/var/spack/repos/spack_repo/builtin
+  myrepo     ~/myrepo
+  builtin    ~/spack/var/spack/repos/builtin
 
 Each repository is listed with its associated namespace.  To get the raw,
 merged YAML from all configuration files, use ``spack config get repos``:
@@ -336,9 +335,9 @@ merged YAML from all configuration files, use ``spack config get repos``:
 .. code-block:: console
 
    $ spack config get repos
-   repos:
-   - ~/my_spack_repos/spack_repo/myrepo
-   - $spack/var/spack/repos/spack_repo/builtin
+   repos:srepos:
+   - ~/myrepo
+   - $spack/var/spack/repos/builtin
 
 Note that, unlike ``spack repo list``, this does not include the
 namespace, which is read from each repo's ``repo.yaml``.
@@ -352,54 +351,66 @@ yourself; you can use the ``spack repo create`` command.
 
 .. code-block:: console
 
-  $ spack repo create ~/my_spack_repos myrepo
+  $ spack repo create myrepo
   ==> Created repo with namespace 'myrepo'.
   ==> To register it with spack, run this command:
-    spack repo add ~/my_spack_repos/spack_repo/myrepo
+    spack repo add ~/myrepo
 
-  $ ls ~/my_spack_repos/spack_repo/myrepo
+  $ ls myrepo
   packages/  repo.yaml
 
-  $ cat ~/my_spack_repos/spack_repo/myrepo/repo.yaml
+  $ cat myrepo/repo.yaml
   repo:
     namespace: 'myrepo'
-    api: v2.0
 
-Namespaces can also be nested, which can be useful if you have
-multiple package repositories for an organization. Spack will
-create the corresponding directory structure for you:
+By default, the namespace of a new repo matches its directory's name.
+You can supply a custom namespace with a second argument, e.g.:
 
 .. code-block:: console
 
-  $ spack repo create ~/my_spack_repos llnl.comp
+  $ spack repo create myrepo llnl.comp
   ==> Created repo with namespace 'llnl.comp'.
   ==> To register it with spack, run this command:
-    spack repo add ~/my_spack_repos/spack_repo/llnl/comp
+    spack repo add ~/myrepo
 
-
-  $ cat ~/my_spack_repos/spack_repo/llnl/comp/repo.yaml
+  $ cat myrepo/repo.yaml
   repo:
     namespace: 'llnl.comp'
-    api: v2.0
+
+You can also create repositories with custom structure with the ``-d/--subdirectory``
+argument, e.g.:
+
+.. code-block:: console
+
+  $ spack repo create -d applications myrepo apps
+  ==> Created repo with namespace 'apps'.
+  ==> To register it with Spack, run this command:
+    spack repo add ~/myrepo
+
+  $ ls myrepo
+  applications/  repo.yaml
+
+  $ cat myrepo/repo.yaml
+  repo:
+    namespace: apps
+    subdirectory: applications
 
 ^^^^^^^^^^^^^^^^^^
 ``spack repo add``
 ^^^^^^^^^^^^^^^^^^
 
 Once your repository is created, you can register it with Spack with
-``spack repo add``. You nee to specify the path to the directory that
-contains the ``repo.yaml`` file.
+``spack repo add``:
 
 .. code-block:: console
 
-   $ spack repo add ~/my_spack_repos/spack_repo/llnl/comp
+   $ spack repo add ./myrepo
    ==> Added repo with namespace 'llnl.comp'.
 
    $ spack repo list
    ==> 2 package repositories.
-  llnl.comp    v2.0    ~/my_spack_repos/spack_repo/llnl/comp
-  builtin      v2.0    ~/spack/var/spack/repos/spack_repo/builtin
-
+   llnl.comp    ~/myrepo
+   builtin      ~/spack/var/spack/repos/builtin
 
 This simply adds the repo to your ``repos.yaml`` file.
 
@@ -421,43 +432,46 @@ By namespace:
 .. code-block:: console
 
   $ spack repo rm llnl.comp
-  ==> Removed repository ~/my_spack_repos/spack_repo/llnl/comp with namespace 'llnl.comp'.
+  ==> Removed repository ~/myrepo with namespace 'llnl.comp'.
 
   $ spack repo list
   ==> 1 package repository.
-  builtin    ~/spack/var/spack/repos/spack_repo/builtin
+  builtin    ~/spack/var/spack/repos/builtin
 
 By path:
 
 .. code-block:: console
 
-  $ spack repo rm ~/my_spack_repos/spack_repo/llnl/comp
-  ==> Removed repository ~/my_spack_repos/spack_repo/llnl/comp
+  $ spack repo rm ~/myrepo
+  ==> Removed repository ~/myrepo
 
   $ spack repo list
   ==> 1 package repository.
-  builtin    ~/spack/var/spack/repos/spack_repo/builtin
+  builtin    ~/spack/var/spack/repos/builtin
 
 --------------------------------
 Repo namespaces and Python
 --------------------------------
 
-Package repositories are implemented as Python packages. To be precise,
-they are `namespace packages
-<https://packaging.python.org/en/latest/guides/packaging-namespace-packages/>`_
-with ``spack_repo`` the top-level namespace, followed by the repository
-namespace as submodules. For example, the builtin repository corresponds
-to the Python module ``spack_repo.builtin.packages``.
+You may have noticed that namespace notation for repositories is similar
+to the notation for namespaces in Python.  As it turns out, you *can*
+treat Spack repositories like Python packages; this is how they are
+implemented.
 
-This structure allows you to extend a ``builtin`` package in your own
+You could, for example, extend a ``builtin`` package in your own
 repository:
 
 .. code-block:: python
 
-   from spack_repo.builtin.packages.mpich.package import Mpich
+   from spack.pkg.builtin.mpich import Mpich
 
    class MyPackage(Mpich):
        ...
 
-Spack populates ``sys.path`` at runtime with the path to the root of your
-package repository's ``spack_repo`` directory.
+Spack repo namespaces are actually Python namespaces tacked on under
+``spack.pkg``.  The search semantics of ``repos.yaml`` are actually
+implemented using Python's built-in `sys.path
+<https://docs.python.org/2/library/sys.html#sys.path>`_ search.  The
+:py:mod:`spack.repo` module implements a custom `Python importer
+<https://docs.python.org/2/library/imp.html>`_.
+

lib/spack/docs/requirements.txt

@@ -1,13 +1,13 @@
-sphinx==8.2.3
+sphinx==8.1.3
 sphinxcontrib-programoutput==0.18
 sphinx_design==0.6.1
 sphinx-rtd-theme==3.0.2
-python-levenshtein==0.27.1
+python-levenshtein==0.26.1
 docutils==0.21.2
 pygments==2.19.1
-urllib3==2.4.0
-pytest==8.3.5
-isort==6.0.1
-black==25.1.0
-flake8==7.2.0
+urllib3==2.3.0
+pytest==8.3.4
+isort==5.13.2
+black==24.10.0
+flake8==7.1.1
 mypy==1.11.1

lib/spack/env/aocc/clang

@@ -0,0 +1 @@
+../cc

lib/spack/env/aocc/clang++

@@ -0,0 +1 @@
+../cpp

lib/spack/env/aocc/flang

@@ -0,0 +1 @@
+../fc

lib/spack/env/arm/armclang

@@ -0,0 +1 @@
+../cc

lib/spack/env/arm/armclang++

@@ -0,0 +1 @@
+../cc

lib/spack/env/arm/armflang

@@ -0,0 +1 @@
+../cc

lib/spack/env/c++

@@ -0,0 +1 @@
+cc

lib/spack/env/c89

@@ -0,0 +1 @@
+cc

lib/spack/env/c99

@@ -0,0 +1 @@
+cc

lib/spack/env/case-insensitive/CC

@@ -0,0 +1 @@
+../cc

lib/spack/env/cc

@@ -0,0 +1,970 @@
+#!/bin/sh -f
+# shellcheck disable=SC2034  # evals in this script fool shellcheck
+#
+# Copyright Spack Project Developers. See COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+#
+# Spack compiler wrapper script.
+#
+# Compiler commands go through this compiler wrapper in Spack builds.
+# The compiler wrapper is a thin layer around the standard compilers.
+# It enables several key pieces of functionality:
+#
+# 1. It allows Spack to swap compilers into and out of builds easily.
+# 2. It adds several options to the compile line so that spack
+#    packages can find their dependencies at build time and run time:
+#      -I and/or -isystem arguments for dependency /include directories.
+#      -L                 arguments for dependency /lib directories.
+#      -Wl,-rpath         arguments for dependency /lib directories.
+#
+
+# Reset IFS to the default: whitespace-separated lists. When we use
+# other separators, we set and reset it.
+unset IFS
+
+# Separator for lists whose names end with `_list`.
+# We pick the alarm bell character, which is highly unlikely to
+# conflict with anything. This is a literal bell character (which
+# we have to use since POSIX sh does not convert escape sequences
+# like '\a' outside of the format argument of `printf`).
+# NOTE: Depending on your editor this may look empty, but it is not.
+readonly lsep=''
+
+# This is an array of environment variables that need to be set before
+# the script runs. They are set by routines in spack.build_environment
+# as part of the package installation process.
+readonly params="\
+SPACK_ENV_PATH
+SPACK_DEBUG_LOG_DIR
+SPACK_DEBUG_LOG_ID
+SPACK_COMPILER_SPEC
+SPACK_CC_RPATH_ARG
+SPACK_CXX_RPATH_ARG
+SPACK_F77_RPATH_ARG
+SPACK_FC_RPATH_ARG
+SPACK_LINKER_ARG
+SPACK_SHORT_SPEC
+SPACK_SYSTEM_DIRS
+SPACK_MANAGED_DIRS"
+
+# Optional parameters that aren't required to be set
+
+# Boolean (true/false/custom) if we want to add debug flags
+# SPACK_ADD_DEBUG_FLAGS
+
+# If a custom flag is requested, it will be defined
+# SPACK_DEBUG_FLAGS
+
+# The compiler input variables are checked for sanity later:
+#   SPACK_CC, SPACK_CXX, SPACK_F77, SPACK_FC
+# The default compiler flags are passed from these variables:
+#   SPACK_CFLAGS, SPACK_CXXFLAGS, SPACK_FFLAGS,
+#   SPACK_LDFLAGS, SPACK_LDLIBS
+# Debug env var is optional; set to "TRUE" for debug logging:
+#   SPACK_DEBUG
+# Test command is used to unit test the compiler script.
+#   SPACK_TEST_COMMAND
+
+# die MESSAGE
+# Print a message and exit with error code 1.
+die() {
+    echo "[spack cc] ERROR: $*"
+    exit 1
+}
+
+# empty VARNAME
+# Return whether the variable VARNAME is unset or set to the empty string.
+empty() {
+    eval "test -z \"\${$1}\""
+}
+
+# setsep LISTNAME
+# Set the global variable 'sep' to the separator for a list with name LISTNAME.
+# There are three types of lists:
+#   1. regular lists end with _list and are separated by $lsep
+#   2. directory lists end with _dirs/_DIRS/PATH(S) and are separated by ':'
+#   3. any other list is assumed to be separated by spaces: " "
+setsep() {
+    case "$1" in
+        *_dirs|*_DIRS|*PATH|*PATHS)
+            sep=':'
+            ;;
+        *_list)
+            sep="$lsep"
+            ;;
+        *)
+            sep=" "
+            ;;
+    esac
+}
+
+# prepend LISTNAME ELEMENT
+#
+# Prepend ELEMENT to the list stored in the variable LISTNAME.
+# Handles empty lists and single-element lists.
+prepend() {
+    varname="$1"
+    elt="$2"
+
+    if empty "$varname"; then
+        eval "$varname=\"\${elt}\""
+    else
+        # Get the appropriate separator for the list we're appending to.
+        setsep "$varname"
+        eval "$varname=\"\${elt}${sep}\${$varname}\""
+    fi
+}
+
+# append LISTNAME ELEMENT [SEP]
+#
+# Append ELEMENT to the list stored in the variable LISTNAME,
+# assuming the list is separated by SEP.
+# Handles empty lists and single-element lists.
+append() {
+    varname="$1"
+    elt="$2"
+
+    if empty "$varname"; then
+        eval "$varname=\"\${elt}\""
+    else
+        # Get the appropriate separator for the list we're appending to.
+        setsep "$varname"
+        eval "$varname=\"\${$varname}${sep}\${elt}\""
+    fi
+}
+
+# extend LISTNAME1 LISTNAME2 [PREFIX]
+#
+# Append the elements stored in the variable LISTNAME2
+# to the list stored in LISTNAME1.
+# If PREFIX is provided, prepend it to each element.
+extend() {
+    # Figure out the appropriate IFS for the list we're reading.
+    setsep "$2"
+    if [ "$sep" != " " ]; then
+        IFS="$sep"
+    fi
+    eval "for elt in \${$2}; do append $1 \"$3\${elt}\"; done"
+    unset IFS
+}
+
+# preextend LISTNAME1 LISTNAME2 [PREFIX]
+#
+# Prepend the elements stored in the list at LISTNAME2
+# to the list at LISTNAME1, preserving order.
+# If PREFIX is provided, prepend it to each element.
+preextend() {
+    # Figure out the appropriate IFS for the list we're reading.
+    setsep "$2"
+    if [ "$sep" != " " ]; then
+        IFS="$sep"
+    fi
+
+    # first, reverse the list to prepend
+    _reversed_list=""
+    eval "for elt in \${$2}; do prepend _reversed_list \"$3\${elt}\"; done"
+
+    # prepend reversed list to preextend in order
+    IFS="${lsep}"
+    for elt in $_reversed_list; do prepend "$1" "$3${elt}"; done
+    unset IFS
+}
+
+execute() {
+    # dump the full command if the caller supplies SPACK_TEST_COMMAND=dump-args
+    if [ -n "${SPACK_TEST_COMMAND=}" ]; then
+        case "$SPACK_TEST_COMMAND" in
+            dump-args)
+                IFS="$lsep"
+                for arg in $full_command_list; do
+                    echo "$arg"
+                done
+                unset IFS
+                exit
+                ;;
+            dump-env-*)
+                var=${SPACK_TEST_COMMAND#dump-env-}
+                eval "printf '%s\n' \"\$0: \$var: \$$var\""
+                ;;
+            *)
+                die "Unknown test command: '$SPACK_TEST_COMMAND'"
+                ;;
+        esac
+    fi
+
+    #
+    # Write the input and output commands to debug logs if it's asked for.
+    #
+    if [ "$SPACK_DEBUG" = TRUE ]; then
+        input_log="$SPACK_DEBUG_LOG_DIR/spack-cc-$SPACK_DEBUG_LOG_ID.in.log"
+        output_log="$SPACK_DEBUG_LOG_DIR/spack-cc-$SPACK_DEBUG_LOG_ID.out.log"
+        echo "[$mode] $command $input_command" >> "$input_log"
+        IFS="$lsep"
+        echo "[$mode] "$full_command_list >> "$output_log"
+        unset IFS
+    fi
+
+    # Execute the full command, preserving spaces with IFS set
+    # to the alarm bell separator.
+    IFS="$lsep"; exec $full_command_list
+    exit
+}
+
+# Fail with a clear message if the input contains any bell characters.
+if eval "[ \"\${*#*${lsep}}\" != \"\$*\" ]"; then
+    die "Compiler command line contains our separator ('${lsep}'). Cannot parse."
+fi
+
+# ensure required variables are set
+for param in $params; do
+    if eval "test -z \"\${${param}:-}\""; then
+        die "Spack compiler must be run from Spack! Input '$param' is missing."
+    fi
+done
+
+# eval this because SPACK_MANAGED_DIRS and SPACK_SYSTEM_DIRS are inputs we don't wanna loop over.
+# moving the eval inside the function would eval it every call.
+eval "\
+path_order() {
+case \"\$1\" in
+    $SPACK_MANAGED_DIRS) return 0 ;;
+    $SPACK_SYSTEM_DIRS) return 2 ;;
+    /*) return 1 ;;
+esac
+}
+"
+
+# path_list functions. Path_lists have 3 parts: spack_store_<list>, <list> and system_<list>,
+# which are used to prioritize paths when assembling the final command line.
+
+# init_path_lists LISTNAME
+# Set <LISTNAME>, spack_store_<LISTNAME>, and system_<LISTNAME> to "".
+init_path_lists() {
+    eval "spack_store_$1=\"\""
+    eval "$1=\"\""
+    eval "system_$1=\"\""
+}
+
+# assign_path_lists LISTNAME1 LISTNAME2
+# Copy contents of LISTNAME2 into LISTNAME1, for each path_list prefix.
+assign_path_lists() {
+    eval "spack_store_$1=\"\${spack_store_$2}\""
+    eval "$1=\"\${$2}\""
+    eval "system_$1=\"\${system_$2}\""
+}
+
+# append_path_lists LISTNAME ELT
+# Append the provided ELT to the appropriate list, based on the result of path_order().
+append_path_lists() {
+    path_order "$2"
+    case $? in
+        0) eval "append spack_store_$1 \"\$2\"" ;;
+        1) eval "append $1 \"\$2\"" ;;
+        2) eval "append system_$1 \"\$2\"" ;;
+    esac
+}
+
+# Check if optional parameters are defined
+# If we aren't asking for debug flags, don't add them
+if [ -z "${SPACK_ADD_DEBUG_FLAGS:-}" ]; then
+    SPACK_ADD_DEBUG_FLAGS="false"
+fi
+
+# SPACK_ADD_DEBUG_FLAGS must be true/false/custom
+is_valid="false"
+for param in "true" "false" "custom"; do
+  if [ "$param" = "$SPACK_ADD_DEBUG_FLAGS" ];  then
+      is_valid="true"
+  fi
+done
+
+# Exit with error if we are given an incorrect value
+if [ "$is_valid" = "false" ]; then
+    die "SPACK_ADD_DEBUG_FLAGS, if defined, must be one of 'true', 'false', or 'custom'."
+fi
+
+# Figure out the type of compiler, the language, and the mode so that
+# the compiler script knows what to do.
+#
+# Possible languages are C, C++, Fortran 77, and Fortran 90.
+# 'command' is set based on the input command to $SPACK_[CC|CXX|F77|F90]
+#
+# 'mode' is set to one of:
+#    vcheck  version check
+#    cpp     preprocess
+#    cc      compile
+#    as      assemble
+#    ld      link
+#    ccld    compile & link
+
+# Note. SPACK_ALWAYS_XFLAGS are applied for all compiler invocations,
+# including version checks (SPACK_XFLAGS variants are not applied
+# for version checks).
+command="${0##*/}"
+comp="CC"
+vcheck_flags=""
+case "$command" in
+    cpp)
+        mode=cpp
+        debug_flags="-g"
+        vcheck_flags="${SPACK_ALWAYS_CPPFLAGS}"
+        ;;
+    cc|c89|c99|gcc|clang|armclang|icc|icx|pgcc|nvc|xlc|xlc_r|fcc|amdclang|cl.exe|craycc)
+        command="$SPACK_CC"
+        language="C"
+        comp="CC"
+        lang_flags=C
+        debug_flags="-g"
+        vcheck_flags="${SPACK_ALWAYS_CFLAGS}"
+        ;;
+    c++|CC|g++|clang++|armclang++|icpc|icpx|pgc++|nvc++|xlc++|xlc++_r|FCC|amdclang++|crayCC)
+        command="$SPACK_CXX"
+        language="C++"
+        comp="CXX"
+        lang_flags=CXX
+        debug_flags="-g"
+        vcheck_flags="${SPACK_ALWAYS_CXXFLAGS}"
+        ;;
+    ftn|f90|fc|f95|gfortran|flang|armflang|ifort|ifx|pgfortran|nvfortran|xlf90|xlf90_r|nagfor|frt|amdflang|crayftn)
+        command="$SPACK_FC"
+        language="Fortran 90"
+        comp="FC"
+        lang_flags=F
+        debug_flags="-g"
+        vcheck_flags="${SPACK_ALWAYS_FFLAGS}"
+        ;;
+    f77|xlf|xlf_r|pgf77)
+        command="$SPACK_F77"
+        language="Fortran 77"
+        comp="F77"
+        lang_flags=F
+        debug_flags="-g"
+        vcheck_flags="${SPACK_ALWAYS_FFLAGS}"
+        ;;
+    ld|ld.gold|ld.lld)
+        mode=ld
+        ;;
+    *)
+        die "Unknown compiler: $command"
+        ;;
+esac
+
+# If any of the arguments below are present, then the mode is vcheck.
+# In vcheck mode, nothing is added in terms of extra search paths or
+# libraries.
+if [ -z "$mode" ] || [ "$mode" = ld ]; then
+    for arg in "$@"; do
+        case $arg in
+            -v|-V|--version|-dumpversion)
+                mode=vcheck
+                break
+                ;;
+        esac
+    done
+fi
+
+# Finish setting up the mode.
+if [ -z "$mode" ]; then
+    mode=ccld
+    for arg in "$@"; do
+        if [ "$arg" = "-E" ]; then
+            mode=cpp
+            break
+        elif [ "$arg" = "-S" ]; then
+            mode=as
+            break
+        elif [ "$arg" = "-c" ]; then
+            mode=cc
+            break
+        fi
+    done
+fi
+
+# This is needed to ensure we set RPATH instead of RUNPATH
+# (or the opposite, depending on the configuration in config.yaml)
+#
+# Documentation on this mechanism is lacking at best. A few sources
+# of information are (note that some of them take explicitly the
+# opposite stance that Spack does):
+#
+# http://blog.qt.io/blog/2011/10/28/rpath-and-runpath/
+# https://wiki.debian.org/RpathIssue
+#
+# The only discussion I could find on enabling new dynamic tags by
+# default on ld is the following:
+#
+# https://sourceware.org/ml/binutils/2013-01/msg00307.html
+#
+dtags_to_add="${SPACK_DTAGS_TO_ADD}"
+dtags_to_strip="${SPACK_DTAGS_TO_STRIP}"
+linker_arg="${SPACK_LINKER_ARG}"
+
+# Set up rpath variable according to language.
+rpath="ERROR: RPATH ARG WAS NOT SET"
+eval "rpath=\${SPACK_${comp}_RPATH_ARG:?${rpath}}"
+
+# Dump the mode and exit if the command is dump-mode.
+if [ "$SPACK_TEST_COMMAND" = "dump-mode" ]; then
+    echo "$mode"
+    exit
+fi
+
+# If, say, SPACK_CC is set but SPACK_FC is not, we want to know. Compilers do not
+# *have* to set up Fortran executables, so we need to tell the user when a build is
+# about to attempt to use them unsuccessfully.
+if [ -z "$command" ]; then
+    die "Compiler '$SPACK_COMPILER_SPEC' does not have a $language compiler configured."
+fi
+
+#
+# Filter '.' and Spack environment directories out of PATH so that
+# this script doesn't just call itself
+#
+new_dirs=""
+IFS=':'
+for dir in $PATH; do
+    addpath=true
+    for spack_env_dir in $SPACK_ENV_PATH; do
+        case "${dir%%/}" in
+            "$spack_env_dir"|'.'|'')
+                addpath=false
+                break
+                ;;
+        esac
+    done
+    if [ $addpath = true ]; then
+        append new_dirs "$dir"
+    fi
+done
+unset IFS
+export PATH="$new_dirs"
+
+if [ "$mode" = vcheck ]; then
+    full_command_list="$command"
+    args="$@"
+    extend full_command_list vcheck_flags
+    extend full_command_list args
+    execute
+fi
+
+# Darwin's linker has a -r argument that merges object files together.
+# It doesn't work with -rpath.
+# This variable controls whether they are added.
+add_rpaths=true
+if [ "$mode" = ld ] || [ "$mode" = ccld ]; then
+    if [ "${SPACK_SHORT_SPEC#*darwin}" != "${SPACK_SHORT_SPEC}" ]; then
+        for arg in "$@"; do
+            if [ "$arg" = "-r" ]; then
+                if [ "$mode" = ld ] || [ "$mode" = ccld ]; then
+                    add_rpaths=false
+                    break
+                fi
+            elif [ "$arg" = "-Wl,-r" ] && [ "$mode" = ccld ]; then
+                add_rpaths=false
+                break
+            fi
+        done
+    fi
+fi
+
+# Save original command for debug logging
+input_command="$*"
+
+#
+# Parse the command line arguments.
+#
+# We extract -L, -I, -isystem and -Wl,-rpath arguments from the
+# command line and recombine them with Spack arguments later.  We
+# parse these out so that we can make sure that system paths come
+# last, that package arguments come first, and that Spack arguments
+# are injected properly.
+#
+# All other arguments, including -l arguments, are treated as
+# 'other_args' and left in their original order.  This ensures that
+# --start-group, --end-group, and other order-sensitive flags continue to
+# work as the caller expects.
+#
+# The libs variable is initialized here for completeness, and it is also
+# used later to inject flags supplied via `ldlibs` on the command
+# line. These come into the wrappers via SPACK_LDLIBS.
+
+# The loop below breaks up the command line into these lists of components.
+# The lists are all bell-separated to be as flexible as possible, as their
+# contents may come from the command line, from ' '-separated lists,
+# ':'-separated lists, etc.
+
+parse_Wl() {
+    while [ $# -ne 0 ]; do
+    if [ "$wl_expect_rpath" = yes ]; then
+        append_path_lists return_rpath_dirs_list "$1"
+        wl_expect_rpath=no
+    else
+        case "$1" in
+            -rpath=*)
+                arg="${1#-rpath=}"
+                if [ -z "$arg" ]; then
+                    shift; continue
+                fi
+                append_path_lists return_rpath_dirs_list "$arg"
+                ;;
+            --rpath=*)
+                arg="${1#--rpath=}"
+                if [ -z "$arg" ]; then
+                    shift; continue
+                fi
+                append_path_lists return_rpath_dirs_list "$arg"
+                ;;
+            -rpath|--rpath)
+                wl_expect_rpath=yes
+                ;;
+            "$dtags_to_strip")
+                ;;
+            -Wl)
+                # Nested -Wl,-Wl means we're in NAG compiler territory. We don't support it.
+                return 1
+                ;;
+            *)
+                append return_other_args_list "-Wl,$1"
+                ;;
+        esac
+    fi
+    shift
+    done
+}
+
+categorize_arguments() {
+
+    unset IFS
+
+    return_other_args_list=""
+    return_isystem_was_used=""
+
+    init_path_lists return_isystem_include_dirs_list
+    init_path_lists return_include_dirs_list
+    init_path_lists return_lib_dirs_list
+    init_path_lists return_rpath_dirs_list
+
+    # Global state for keeping track of -Wl,-rpath -Wl,/path
+    wl_expect_rpath=no
+
+    # Same, but for -Xlinker -rpath -Xlinker /path
+    xlinker_expect_rpath=no
+
+    while [ $# -ne 0 ]; do
+
+        # an RPATH to be added after the case statement.
+        rp=""
+
+        # Multiple consecutive spaces in the command line can
+        # result in blank arguments
+        if [ -z "$1" ]; then
+            shift
+            continue
+        fi
+
+        if [ -n "${SPACK_COMPILER_FLAGS_KEEP}" ] ; then
+            # NOTE: the eval is required to allow `|` alternatives inside the variable
+            eval "\
+            case \"\$1\" in
+                $SPACK_COMPILER_FLAGS_KEEP)
+                    append return_other_args_list \"\$1\"
+                    shift
+                    continue
+                    ;;
+            esac
+            "
+        fi
+        # the replace list is a space-separated list of pipe-separated pairs,
+        # the first in each pair is the original prefix to be matched, the
+        # second is the replacement prefix
+        if [ -n "${SPACK_COMPILER_FLAGS_REPLACE}" ] ; then
+            for rep in ${SPACK_COMPILER_FLAGS_REPLACE} ; do
+                before=${rep%|*}
+                after=${rep#*|}
+                eval "\
+                stripped=\"\${1##$before}\"
+                "
+                if [ "$stripped" = "$1" ] ; then
+                    continue
+                fi
+
+                replaced="$after$stripped"
+
+                # it matched, remove it
+                shift
+
+                if [ -z "$replaced" ] ; then
+                    # completely removed, continue OUTER loop
+                    continue 2
+                fi
+
+                # re-build argument list with replacement
+                set -- "$replaced" "$@"
+            done
+        fi
+
+        case "$1" in
+            -isystem*)
+                arg="${1#-isystem}"
+                return_isystem_was_used=true
+                if [ -z "$arg" ]; then shift; arg="$1"; fi
+                append_path_lists return_isystem_include_dirs_list "$arg"
+                ;;
+            -I*)
+                arg="${1#-I}"
+                if [ -z "$arg" ]; then shift; arg="$1"; fi
+                append_path_lists return_include_dirs_list "$arg"
+                ;;
+            -L*)
+                arg="${1#-L}"
+                if [ -z "$arg" ]; then shift; arg="$1"; fi
+                append_path_lists return_lib_dirs_list "$arg"
+                ;;
+            -l*)
+                # -loopopt=0 is generated erroneously in autoconf <= 2.69,
+                # and passed by ifx to the linker, which confuses it with a
+                # library. Filter it out.
+                # TODO: generalize filtering of args with an env var, so that
+                # TODO: we do not have to special case this here.
+                if { [ "$mode" = "ccld" ] || [ $mode = "ld" ]; } \
+                    && [ "$1" != "${1#-loopopt}" ]; then
+                    shift
+                    continue
+                fi
+                arg="${1#-l}"
+                if [ -z "$arg" ]; then shift; arg="$1"; fi
+                append return_other_args_list "-l$arg"
+                ;;
+            -Wl,*)
+                IFS=,
+                if ! parse_Wl ${1#-Wl,}; then
+                    append return_other_args_list "$1"
+                fi
+                unset IFS
+                ;;
+            -Xlinker)
+                shift
+                if [ $# -eq 0 ]; then
+                    # -Xlinker without value: let the compiler error about it.
+                    append return_other_args_list -Xlinker
+                    xlinker_expect_rpath=no
+                    break
+                elif [ "$xlinker_expect_rpath" = yes ]; then
+                    # Register the path of -Xlinker -rpath <other args> -Xlinker <path>
+                    append_path_lists return_rpath_dirs_list "$1"
+                    xlinker_expect_rpath=no
+                else
+                    case "$1" in
+                        -rpath=*)
+                            arg="${1#-rpath=}"
+                            append_path_lists return_rpath_dirs_list "$arg"
+                            ;;
+                        --rpath=*)
+                            arg="${1#--rpath=}"
+                            append_path_lists return_rpath_dirs_list "$arg"
+                            ;;
+                        -rpath|--rpath)
+                            xlinker_expect_rpath=yes
+                            ;;
+                        "$dtags_to_strip")
+                            ;;
+                        *)
+                            append return_other_args_list -Xlinker
+                            append return_other_args_list "$1"
+                            ;;
+                    esac
+                fi
+                ;;
+            "$dtags_to_strip")
+                ;;
+            *)
+                # if mode is not ld, we can just add to other args
+                if [ "$mode" != "ld" ]; then
+                    append return_other_args_list "$1"
+                    shift
+                    continue
+                fi
+
+                # if we're in linker mode, we need to parse raw RPATH args
+                case "$1" in
+                    -rpath=*)
+                        arg="${1#-rpath=}"
+                        append_path_lists return_rpath_dirs_list "$arg"
+                        ;;
+                    --rpath=*)
+                        arg="${1#--rpath=}"
+                        append_path_lists return_rpath_dirs_list "$arg"
+                        ;;
+                    -rpath|--rpath)
+                        if [ $# -eq 1 ]; then
+                            # -rpath without value: let the linker raise an error.
+                            append return_other_args_list "$1"
+                            break
+                        fi
+                        shift
+                        append_path_lists return_rpath_dirs_list "$1"
+                        ;;
+                    *)
+                        append return_other_args_list "$1"
+                        ;;
+                esac
+                ;;
+        esac
+        shift
+    done
+
+    # We found `-Xlinker -rpath` but no matching value `-Xlinker /path`. Just append
+    # `-Xlinker -rpath` again and let the compiler or linker handle the error during arg
+    # parsing.
+    if [ "$xlinker_expect_rpath" = yes ]; then
+        append return_other_args_list -Xlinker
+        append return_other_args_list -rpath
+    fi
+
+    # Same, but for -Wl flags.
+    if [ "$wl_expect_rpath" = yes ]; then
+        append return_other_args_list -Wl,-rpath
+    fi
+}
+
+categorize_arguments "$@"
+
+assign_path_lists isystem_include_dirs_list return_isystem_include_dirs_list
+assign_path_lists include_dirs_list return_include_dirs_list
+assign_path_lists lib_dirs_list return_lib_dirs_list
+assign_path_lists rpath_dirs_list return_rpath_dirs_list
+
+isystem_was_used="$return_isystem_was_used"
+other_args_list="$return_other_args_list"
+
+#
+# Add flags from Spack's cppflags, cflags, cxxflags, fcflags, fflags, and
+# ldflags. We stick to the order that gmake puts the flags in by default.
+#
+# See the gmake manual on implicit rules for details:
+# https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html
+#
+flags_list=""
+
+# Add debug flags
+if [ "${SPACK_ADD_DEBUG_FLAGS}" = "true" ]; then
+    extend flags_list debug_flags
+
+# If a custom flag is requested, derive from environment
+elif [ "$SPACK_ADD_DEBUG_FLAGS" = "custom" ]; then
+    extend flags_list SPACK_DEBUG_FLAGS
+fi
+
+spack_flags_list=""
+
+# Fortran flags come before CPPFLAGS
+case "$mode" in
+    cc|ccld)
+        case $lang_flags in
+            F)
+                extend spack_flags_list SPACK_ALWAYS_FFLAGS
+                extend spack_flags_list SPACK_FFLAGS
+                ;;
+        esac
+        ;;
+esac
+
+# C preprocessor flags come before any C/CXX flags
+case "$mode" in
+    cpp|as|cc|ccld)
+        extend spack_flags_list SPACK_ALWAYS_CPPFLAGS
+        extend spack_flags_list SPACK_CPPFLAGS
+        ;;
+esac
+
+
+# Add C and C++ flags
+case "$mode" in
+    cc|ccld)
+        case $lang_flags in
+            C)
+                extend spack_flags_list SPACK_ALWAYS_CFLAGS
+                extend spack_flags_list SPACK_CFLAGS
+                ;;
+            CXX)
+                extend spack_flags_list SPACK_ALWAYS_CXXFLAGS
+                extend spack_flags_list SPACK_CXXFLAGS
+                ;;
+        esac
+
+        # prepend target args
+        preextend flags_list SPACK_TARGET_ARGS
+        ;;
+esac
+
+# Linker flags
+case "$mode" in
+    ccld)
+        extend spack_flags_list SPACK_LDFLAGS
+        ;;
+esac
+
+IFS="$lsep"
+    categorize_arguments $spack_flags_list
+unset IFS
+
+assign_path_lists spack_flags_isystem_include_dirs_list return_isystem_include_dirs_list
+assign_path_lists spack_flags_include_dirs_list return_include_dirs_list
+assign_path_lists spack_flags_lib_dirs_list return_lib_dirs_list
+assign_path_lists spack_flags_rpath_dirs_list return_rpath_dirs_list
+
+spack_flags_isystem_was_used="$return_isystem_was_used"
+spack_flags_other_args_list="$return_other_args_list"
+
+
+# On macOS insert headerpad_max_install_names linker flag
+if [ "$mode" = ld ] || [ "$mode" = ccld ]; then
+    if [ "${SPACK_SHORT_SPEC#*darwin}" != "${SPACK_SHORT_SPEC}" ]; then
+        case "$mode" in
+            ld)
+                append flags_list "-headerpad_max_install_names" ;;
+            ccld)
+                append flags_list "-Wl,-headerpad_max_install_names" ;;
+        esac
+    fi
+fi
+
+if [ "$mode" = ccld ] || [ "$mode" = ld ]; then
+    if [ "$add_rpaths" != "false" ]; then
+        # Append RPATH directories. Note that in the case of the
+        # top-level package these directories may not exist yet. For dependencies
+        # it is assumed that paths have already been confirmed.
+        extend spack_store_rpath_dirs_list SPACK_STORE_RPATH_DIRS
+        extend rpath_dirs_list SPACK_RPATH_DIRS
+    fi
+fi
+
+if [ "$mode" = ccld ] || [ "$mode" = ld ]; then
+    extend spack_store_lib_dirs_list SPACK_STORE_LINK_DIRS
+    extend lib_dirs_list SPACK_LINK_DIRS
+fi
+
+libs_list=""
+
+# add RPATHs if we're in in any linking mode
+case "$mode" in
+    ld|ccld)
+        # Set extra RPATHs
+        extend lib_dirs_list SPACK_COMPILER_EXTRA_RPATHS
+        if [ "$add_rpaths" != "false" ]; then
+            extend rpath_dirs_list SPACK_COMPILER_EXTRA_RPATHS
+        fi
+
+        # Set implicit RPATHs
+        if [ "$add_rpaths" != "false" ]; then
+            extend rpath_dirs_list SPACK_COMPILER_IMPLICIT_RPATHS
+        fi
+
+        # Add SPACK_LDLIBS to args
+        for lib in $SPACK_LDLIBS; do
+            append libs_list "${lib#-l}"
+        done
+        ;;
+esac
+
+case "$mode" in
+    cpp|cc|as|ccld)
+        if [ "$spack_flags_isystem_was_used" = "true" ] || [ "$isystem_was_used" = "true" ]; then
+            extend spack_store_isystem_include_dirs_list SPACK_STORE_INCLUDE_DIRS
+            extend isystem_include_dirs_list SPACK_INCLUDE_DIRS
+        else
+            extend spack_store_include_dirs_list SPACK_STORE_INCLUDE_DIRS
+            extend include_dirs_list SPACK_INCLUDE_DIRS
+        fi
+        ;;
+esac
+
+#
+# Finally, reassemble the command line.
+#
+args_list="$flags_list"
+
+# Include search paths partitioned by (in store, non-sytem, system)
+# NOTE: adding ${lsep} to the prefix here turns every added element into two
+extend args_list spack_store_spack_flags_include_dirs_list -I
+extend args_list spack_store_include_dirs_list -I
+
+extend args_list spack_flags_include_dirs_list -I
+extend args_list include_dirs_list -I
+
+extend args_list spack_store_spack_flags_isystem_include_dirs_list "-isystem${lsep}"
+extend args_list spack_store_isystem_include_dirs_list "-isystem${lsep}"
+
+extend args_list spack_flags_isystem_include_dirs_list "-isystem${lsep}"
+extend args_list isystem_include_dirs_list "-isystem${lsep}"
+
+extend args_list system_spack_flags_include_dirs_list -I
+extend args_list system_include_dirs_list -I
+
+extend args_list system_spack_flags_isystem_include_dirs_list "-isystem${lsep}"
+extend args_list system_isystem_include_dirs_list "-isystem${lsep}"
+
+# Library search paths partitioned by (in store, non-sytem, system)
+extend args_list spack_store_spack_flags_lib_dirs_list "-L"
+extend args_list spack_store_lib_dirs_list "-L"
+
+extend args_list spack_flags_lib_dirs_list "-L"
+extend args_list lib_dirs_list "-L"
+
+extend args_list system_spack_flags_lib_dirs_list "-L"
+extend args_list system_lib_dirs_list "-L"
+
+# RPATHs arguments
+rpath_prefix=""
+case "$mode" in
+    ccld)
+        if [ -n "$dtags_to_add" ] ; then
+            append args_list "$linker_arg$dtags_to_add"
+        fi
+        rpath_prefix="$rpath"
+        ;;
+    ld)
+        if [ -n "$dtags_to_add" ] ; then
+            append args_list "$dtags_to_add"
+        fi
+        rpath_prefix="-rpath${lsep}"
+        ;;
+esac
+
+# if mode is ccld or ld, extend RPATH lists with the prefix determined above
+if [ -n "$rpath_prefix" ]; then
+    extend args_list spack_store_spack_flags_rpath_dirs_list "$rpath_prefix"
+    extend args_list spack_store_rpath_dirs_list "$rpath_prefix"
+
+    extend args_list spack_flags_rpath_dirs_list "$rpath_prefix"
+    extend args_list rpath_dirs_list "$rpath_prefix"
+
+    extend args_list system_spack_flags_rpath_dirs_list "$rpath_prefix"
+    extend args_list system_rpath_dirs_list "$rpath_prefix"
+fi
+
+# Other arguments from the input command
+extend args_list other_args_list
+extend args_list spack_flags_other_args_list
+
+# Inject SPACK_LDLIBS, if supplied
+extend args_list libs_list "-l"
+
+full_command_list="$command"
+extend full_command_list args_list
+
+# prepend the ccache binary if we're using ccache
+if [ -n "$SPACK_CCACHE_BINARY" ]; then
+    case "$lang_flags" in
+        C|CXX)  # ccache only supports C languages
+            prepend full_command_list "${SPACK_CCACHE_BINARY}"
+            # workaround for stage being a temp folder
+            # see #3761#issuecomment-294352232
+            export CCACHE_NOHASHDIR=yes
+            ;;
+    esac
+fi
+
+execute

lib/spack/env/cce/case-insensitive/CC

@@ -0,0 +1 @@
+../../cc

lib/spack/env/cce/case-insensitive/crayCC

@@ -0,0 +1 @@
+../../cc

lib/spack/env/cce/cc

@@ -0,0 +1 @@
+../cc

lib/spack/env/cce/craycc

@@ -0,0 +1 @@
+../cc

lib/spack/env/cce/crayftn

@@ -0,0 +1 @@
+../cc

lib/spack/env/cce/ftn

@@ -0,0 +1 @@
+../cc

lib/spack/env/clang/clang

@@ -0,0 +1 @@
+../cc

lib/spack/env/clang/clang++

@@ -0,0 +1 @@
+../cc

lib/spack/env/clang/flang

@@ -0,0 +1 @@
+../cc

lib/spack/env/clang/gfortran

@@ -0,0 +1 @@
+../cc

lib/spack/env/cpp

@@ -0,0 +1 @@
+cc

lib/spack/env/f77

@@ -0,0 +1 @@
+cc

lib/spack/env/f90

@@ -0,0 +1 @@
+cc

lib/spack/env/f95

@@ -0,0 +1 @@
+cc

lib/spack/env/fc

@@ -0,0 +1 @@
+cc

lib/spack/env/fj/case-insensitive/FCC

@@ -0,0 +1 @@
+../../cc

lib/spack/env/fj/fcc

@@ -0,0 +1 @@
+../cc

lib/spack/env/fj/frt

@@ -0,0 +1 @@
+../cc

lib/spack/env/ftn

@@ -0,0 +1 @@
+cc

lib/spack/env/gcc/g++

@@ -0,0 +1 @@
+../cc

lib/spack/env/gcc/gcc

@@ -0,0 +1 @@
+../cc

lib/spack/env/gcc/gfortran

@@ -0,0 +1 @@
+../cc

lib/spack/env/intel/icc

@@ -0,0 +1 @@
+../cc

lib/spack/env/intel/icpc

@@ -0,0 +1 @@
+../cc

lib/spack/env/intel/ifort

@@ -0,0 +1 @@
+../cc

lib/spack/env/ld

@@ -0,0 +1 @@
+cc

lib/spack/env/ld.gold

@@ -0,0 +1 @@
+cc

lib/spack/env/ld.lld

@@ -0,0 +1 @@
+cc

lib/spack/env/nag/nagfor

@@ -0,0 +1 @@
+../cc

lib/spack/env/nvhpc/nvc

@@ -0,0 +1 @@
+../cc

lib/spack/env/nvhpc/nvc++

@@ -0,0 +1 @@
+../cc

lib/spack/env/nvhpc/nvfortran

@@ -0,0 +1 @@
+../cc

lib/spack/env/oneapi/dpcpp

@@ -0,0 +1 @@
+../cc

lib/spack/env/oneapi/icpx

@@ -0,0 +1 @@
+../cc

lib/spack/env/oneapi/icx

@@ -0,0 +1 @@
+../cc

lib/spack/env/oneapi/ifx

@@ -0,0 +1 @@
+../cc

lib/spack/env/pgi/pgc++

@@ -0,0 +1 @@
+../cc

lib/spack/env/pgi/pgcc

@@ -0,0 +1 @@
+../cc

lib/spack/env/pgi/pgfortran

@@ -0,0 +1 @@
+../cc