CI Set COMMIT_MESSAGE to allow commit markers detection in unit-tests.yml (scikit-learn#32501)

Author: thomass-dev

.github/workflows/unit-tests.yml

@@ -41,11 +41,35 @@ jobs:
           pip install ninja meson scipy
           python build_tools/check-meson-openmp-dependencies.py
 
+  retrieve-commit-message:
+    name: Retrieve the latest commit message
+    runs-on: ubuntu-latest
+    if: github.repository == 'scikit-learn/scikit-learn'
+    outputs:
+      message: ${{ steps.git-log.outputs.message }}
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+      - id: git-log
+        name: Set commit message job output
+        shell: bash
+        run: |
+          set -eu
+
+          message=$(git log --format=%B -n 1)
+
+          {
+            echo 'message<<EOF'
+            echo "${message}"
+            echo EOF
+          } >> "${GITHUB_OUTPUT}"
+
   unit-tests:
     name: ${{ matrix.name }}
     runs-on: ${{ matrix.os }}
     if: github.repository == 'scikit-learn/scikit-learn'
-    needs: [lint]
+    needs: [lint, retrieve-commit-message]
     strategy:
       # Ensures that all builds run to completion even if one of them fails
       fail-fast: false
@@ -88,6 +112,8 @@ jobs:
 
       - name: Run tests
         run: bash -l build_tools/azure/test_script.sh
+        env:
+          COMMIT_MESSAGE: ${{ needs.retrieve-commit-message.outputs.message }}
 
       - name: Combine coverage reports from parallel test runners
         run: bash -l build_tools/azure/combine_coverage_reports.sh

build_tools/azure/test_script.sh

@@ -22,7 +22,15 @@ if [[ "$BUILD_REASON" == "Schedule" ]]; then
     export SKLEARN_RUN_FLOAT32_TESTS=1
 fi
 
-COMMIT_MESSAGE=$(python build_tools/azure/get_commit_message.py --only-show-message)
+# In GitHub Action (especially in `.github/workflows/unit-tests.yml` which
+# calls this script), the environment variable `COMMIT_MESSAGE` is already set
+# to the latest commit message.
+if [[ -z "${COMMIT_MESSAGE+x}" ]]; then
+    # If 'COMMIT_MESSAGE' is unset we are in Azure, and we retrieve the commit
+    # message via the get_commit_message.py script which uses Azure-specific
+    # variables, for example 'BUILD_SOURCEVERSIONMESSAGE'.
+    COMMIT_MESSAGE=$(python build_tools/azure/get_commit_message.py --only-show-message)
+fi
 
 if [[ "$COMMIT_MESSAGE" =~ \[float32\] ]]; then
     echo "float32 tests will be run due to commit message"