GridTools · wdeconinck · Apr 30, 2026 · Apr 30, 2026 · May 4, 2026 · May 4, 2026
diff --git a/.github/actions/setup-build-env/action.yml b/.github/actions/setup-build-env/action.yml
@@ -0,0 +1,66 @@
+name: Setup atlas4py build environment
+description: Install system + Python build dependencies for atlas4py on Linux/macOS.
+
+inputs:
+  python-version:
+    description: Python version to set up
+    required: true
+  install-build-backend:
+    description: >
+      Whether to pre-install pybind11, scikit-build-core and numpy into the
+      host environment. Required for `--no-build-isolation` builds; can be
+      skipped when pip provisions an isolated build environment.
+    required: false
+    default: 'false'
+
+outputs:
+  sys-deps-cache-key:
+    description: >-
+      A string encoding the versions of installed system libraries (e.g. MPI).
+      Include this in cache keys that depend on compiled system dependencies.
+    value: ${{ steps.sys-deps-key.outputs.value }}
+
+runs:
+  using: composite
+  steps:
+    - name: Set up Python ${{ inputs.python-version }}
+      uses: actions/setup-python@v6
+      with:
+        python-version: ${{ inputs.python-version }}
+
+    - name: Install system build dependencies (Linux)
+      if: runner.os == 'Linux'
+      shell: bash
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y --no-install-recommends \
+          build-essential libopenmpi-dev openmpi-bin libomp-dev
+
+    - name: Install system build dependencies (macOS)
+      if: runner.os == 'macOS'
+      shell: bash
+      run: |
+        brew update
+        brew install open-mpi
+
+    - name: Collect system library versions for cache key
+      id: sys-deps-key
+      shell: bash
+      run: |
+        if [ "$RUNNER_OS" = "Linux" ]; then
+          MPI_VERSION=$(dpkg-query --showformat='${Version}' --show libopenmpi-dev)
+          OMP_VERSION=$(dpkg-query --showformat='${Version}' --show libomp-dev)
+          echo "value=mpi-${MPI_VERSION}-omp-${OMP_VERSION}" >> "$GITHUB_OUTPUT"
+        else
+          MPI_VERSION=$(brew list --versions open-mpi | awk '{print $2}')
+          echo "value=mpi-${MPI_VERSION}" >> "$GITHUB_OUTPUT"
+        fi
+
+    - name: Upgrade pip
+      shell: bash
+      run: python -m pip install --upgrade pip
+
+    - name: Install Python build backend (for --no-build-isolation builds)
+      if: inputs.install-build-backend == 'true'
+      shell: bash
+      run: python -m pip install pybind11 scikit-build-core numpy
diff --git a/.github/actions/verify-atlas4py-rebuild/action.yml b/.github/actions/verify-atlas4py-rebuild/action.yml
@@ -0,0 +1,39 @@
+name: Verify atlas4py editable rebuild
+description: >
+  Verify that an editable install of atlas4py picks up edits to both Python
+  and C++ sources (i.e. that scikit-build-core's editable.rebuild works).
+
+runs:
+  using: composite
+  steps:
+    - name: Verify editable Python edits are picked up
+      shell: bash
+      run: |
+        python - <<'PY'
+        import pathlib
+        path = pathlib.Path("src/atlas4py/__init__.py")
+        marker = "\n__CI_EDITABLE_MARKER__ = 'changed'\n"
+        txt = path.read_text(encoding="utf-8")
+        if marker not in txt:
+            path.write_text(txt + marker, encoding="utf-8")
+        import atlas4py
+        assert getattr(atlas4py, "__CI_EDITABLE_MARKER__", None) == "changed"
+        print("Editable Python change reflected OK")
+        PY
+
+    - name: Verify editable C++ edits trigger a rebuild
+      shell: bash
+      run: |
+        sed -i.bak 's/ATLAS4PY_VERSION_STRING/__CI_EDITABLE_MARKER__/g' \
+          src/atlas4py/_atlas4py.cpp && rm -f src/atlas4py/_atlas4py.cpp.bak
+        python - <<'PY'
+        import atlas4py
+        assert atlas4py.__version__ == "__CI_EDITABLE_MARKER__", atlas4py.__version__
+        print("Editable C++ change reflected OK")
+        PY
+
+    - name: Restore edited sources
+      if: always()
+      shell: bash
+      run: |
+        git checkout -- src/atlas4py/__init__.py src/atlas4py/_atlas4py.cpp || true
diff --git a/.github/actions/verify-atlas4py/action.yml b/.github/actions/verify-atlas4py/action.yml
@@ -0,0 +1,27 @@
+name: Verify atlas4py installation
+description: Common smoke tests run after an atlas4py install (import, version, pytest).
+
+runs:
+  using: composite
+  steps:
+    - name: Verify import
+      shell: bash
+      env:
+        ATLAS_DEBUG: "1"
+      run: python -c "import atlas4py; print('atlas4py', atlas4py.__version__, 'imported successfully')"
+
+    - name: Verify version matches pyproject.toml
+      shell: bash
+      run: |
+        python - <<'PY'
+        import tomllib, pathlib, atlas4py
+        expected = tomllib.loads(pathlib.Path("pyproject.toml").read_text())["project"]["version"]
+        assert atlas4py.__version__ == expected, (atlas4py.__version__, expected)
+        print("Version OK:", expected)
+        PY
+
+    - name: Run pytest suite
+      shell: bash
+      run: |
+        python -m pip install pytest
+        pytest -v tests
diff --git a/.github/workflows/cibuildwheel.yml b/.github/workflows/cibuildwheel.yml
@@ -1,15 +1,29 @@
 name: Build and deploy wheel
 
 on:
+  # Trigger the workflow on all pushes, except on tag creation
   push:
-    branches: [ master ]
-  pull_request:
-    branches: [ master ]
+    branches:
+    - '**'
+    tags-ignore:
+    - '**'
 
+  # Trigger the workflow on all pull requests
+  pull_request: ~
+
+  # Allow workflow to be dispatched on demand
+  workflow_dispatch: ~
 jobs:
+  pre-check:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Condition met, proceeding with workflow."
+
   build_wheels:
     name: Build wheels on ${{ matrix.os }} for ${{ matrix.python }}
     runs-on: ${{ matrix.os }}
+    needs: pre-check # This job won't start if 'pre-check' is skipped
     strategy:
       matrix:
         os:
@@ -41,24 +55,27 @@ jobs:
           CIBW_TEST_REQUIRES: -r requirements-dev.txt
           CIBW_TEST_COMMAND: pytest -v {project}/tests
       - name: Upload artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: wheel-${{matrix.python}}-${{ matrix.os }}
           path: ./dist/*.whl
 
   build_sdist:
     name: Build sdist
     runs-on: ubuntu-latest
+    needs: pre-check # This job won't start if 'pre-check' is skipped
     steps:
       - name: Set up Python
-        uses: actions/setup-python@v2
-      - uses: actions/checkout@v4
+        uses: actions/setup-python@v6
+        with:
+          python-version: '3.13'
+      - uses: actions/checkout@v6
       - name: Install requirements
         run: python -m pip install -r requirements-dev.txt
       - name: Make sdist
         run:  python -m build --sdist --outdir dist/
       - name: Upload artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: sdist
           path: ./dist/*.tar.gz
@@ -67,8 +84,12 @@ jobs:
     name: Upload wheels to TestPyPI
     needs: [build_wheels, build_sdist]
     runs-on: ubuntu-latest
+
+    # Only run for pushes to master (not PRs, not workflow_dispatch)
+    if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/master' }}
+
     steps:
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@v8
         with:
           path: dist
           merge-multiple: true

diff --git a/.github/workflows/editable-install.yml b/.github/workflows/editable-install.yml
@@ -0,0 +1,175 @@
+name: Editable install tests
+
+on:
+  push:
+    branches:
+      - '**'
+    tags-ignore:
+      - '**'
+  pull_request: ~
+  workflow_dispatch: ~
+
+jobs:
+  # ---------------------------------------------------------------------------
+  # Editable install using the bundled (FetchContent) eckit + atlas dependencies
+  # ---------------------------------------------------------------------------
+  editable-internal:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
+    name: Editable (bundled) - ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+        python-version: ["3.13"]
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Setup build environment
+        uses: ./.github/actions/setup-build-env
+        with:
+          python-version: ${{ matrix.python-version }}
+          # Pre-install build backend only when we will skip pip's build isolation.
+          install-build-backend: 'true'
+
+      - name: Editable install
+        run: |
+            export CMAKE_ARGS="-DATLAS_ENABLE_OMP=ON"
+            python -m pip install --no-build-isolation -v -e .
+
+      # ----- Verification --------------------------------------------------
+      - name: Verify atlas4py installation
+        uses: ./.github/actions/verify-atlas4py
+
+      # ----- Editable-rebuild specific checks ------------------------------
+      - name: Verify atlas4py editable rebuild
+        uses: ./.github/actions/verify-atlas4py-rebuild
+
+  # ---------------------------------------------------------------------------
+  # Editable install using externally built eckit + atlas
+  # ---------------------------------------------------------------------------
+  editable-external:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
+    name: Editable (external) - ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+        python-version: ["3.13"]
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Setup build environment
+        uses: ./.github/actions/setup-build-env
+        id: build-env
+        with:
+          python-version: ${{ matrix.python-version }}
+          install-build-backend: 'true'
+
+      - name: Extract pinned dependency versions from pyproject.toml
+        id: versions
+        run: |
+          python - <<'PY' >> "$GITHUB_ENV"
+          import pathlib, re, tomllib
+          cfg = tomllib.loads(pathlib.Path("pyproject.toml").read_text())
+          args = cfg["tool"]["scikit-build"]["cmake"]["args"]
+          pat = re.compile(r"^-D(ATLAS4PY_[A-Za-z0-9_]+)=(.*)$")
+          for a in args:
+              m = pat.match(a)
+              if m:
+                  print(f"{m.group(1)}={m.group(2)}")
+          PY
+
+      - name: Cache external eckit + atlas install
+        id: cache-deps
+        uses: actions/cache@v5
+        with:
+          path: deps/install
+          key: ext-deps-atlas-${{ env.ATLAS4PY_ATLAS_VERSION }}-eckit-${{ env.ATLAS4PY_ECKIT_VERSION }}-ecbuild-${{ env.ATLAS4PY_ECBUILD_VERSION }}-${{ runner.os }}[${{ steps.build-env.outputs.sys-deps-cache-key }}]
+
+      - name: Build external eckit + atlas
+        if: steps.cache-deps.outputs.cache-hit != 'true'
+        run: |
+          mkdir -p deps/source
+          pushd deps
+
+          echo "::group::Clone ecbuild ${ATLAS4PY_ECBUILD_VERSION}"
+          git clone --branch ${ATLAS4PY_ECBUILD_VERSION} --single-branch https://github.com/ecmwf/ecbuild source/ecbuild
+          echo "::endgroup::"
+
+          echo "::group::Clone eckit ${ATLAS4PY_ECKIT_VERSION}"
+          git clone --branch ${ATLAS4PY_ECKIT_VERSION}   --single-branch https://github.com/ecmwf/eckit   source/eckit
+          echo "::endgroup::"
+
+          echo "::group::Clone atlas ${ATLAS4PY_ATLAS_VERSION}"
+          git clone --branch ${ATLAS4PY_ATLAS_VERSION}   --single-branch https://github.com/ecmwf/atlas   source/atlas
+          echo "::endgroup::"
+
+          export CMAKE_PREFIX_PATH=$PWD/install
+
+          echo "::group::Configure eckit"
+          cmake -S source/eckit -B build/eckit -G Ninja \
+            -DENABLE_TESTS=OFF -DENABLE_FORTRAN=OFF -DCMAKE_BUILD_TYPE=Release
+          echo "::endgroup::"
+
+          echo "::group::Build eckit"
+          cmake --build build/eckit --parallel
+          echo "::endgroup::"
+
+          echo "::group::Install eckit"
+          cmake --install build/eckit --prefix install/eckit
+          echo "::endgroup::"
+
+          echo "::group::Configure atlas"
+          cmake -S source/atlas -B build/atlas -G Ninja \
+            -DENABLE_TESTS=OFF -DENABLE_FORTRAN=OFF -DCMAKE_BUILD_TYPE=Release
+          echo "::endgroup::"
+
+          echo "::group::Build atlas"
+          cmake --build build/atlas --parallel
+          echo "::endgroup::"
+
+          echo "::group::Install atlas"
+          cmake --install build/atlas --prefix install/atlas
+          echo "::endgroup::"
+
+          popd
+
+      - name: Editable install against external deps
+        run: |
+          export CMAKE_PREFIX_PATH=$PWD/deps/install
+          python -m pip install --no-build-isolation -v -e .
+
+      # ----- Verification --------------------------------------------------
+      - name: Verify atlas4py installation
+        uses: ./.github/actions/verify-atlas4py
+
+      # ----- External-deps specific check ----------------------------------
+      - name: Verify atlas4py was linked against the external atlas
+        run: |
+          python - <<'PY'
+          import pathlib, platform, subprocess, atlas4py._atlas4py as _ext
+          ext = pathlib.Path(_ext.__file__).resolve()
+          print(ext)
+          if platform.system() == "Darwin":
+              # `otool -l` dumps load commands, including LC_RPATH entries which
+              # carry the absolute external install path baked in at link time.
+              out = subprocess.check_output(["otool", "-l", str(ext)]).decode()
+          else:
+              out = subprocess.check_output(["ldd", str(ext)]).decode()
+          print(out)
+          assert "libatlas" in out, "libatlas not linked"
+          # Must resolve to our externally-installed atlas
+          external = str(pathlib.Path("deps/install/atlas").resolve())
+          assert external in out, f"expected external atlas path {external} in linker output"
+          print("External atlas linkage OK")
+          PY
+
+      # ----- Editable-rebuild specific checks ------------------------------
+      - name: Verify atlas4py editable rebuild
+        uses: ./.github/actions/verify-atlas4py-rebuild