Generate and publish build constraints

.github/workflows/generate-constraints.yml

@@ -135,7 +135,9 @@ jobs:
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
         with:
           name: constraints-${{ matrix.python-version }}
-          path: ./files/constraints-${{ matrix.python-version }}/constraints-*.txt
+          path: |
+            ./files/constraints-${{ matrix.python-version }}/constraints-*.txt
+            ./files/constraints-${{ matrix.python-version }}/build-constraints-*.txt
           retention-days: 7
           if-no-files-found: error
       - name: "Dependency upgrade summary"

dev/MANUALLY_GENERATING_IMAGE_CACHE_AND_CONSTRAINTS.md

@@ -224,17 +224,17 @@ breeze release-management generate-constraints --airflow-constraints-mode constr
 AIRFLOW_SOURCES=$(pwd)
 ```
 
-The constraints will be generated in `files/constraints-PYTHON_VERSION/constraints-*.txt` files. You need to
-check out the right 'constraints-' branch in a separate repository, and then you can copy, commit and push the
-generated files.
+The constraints will be generated in `files/constraints-PYTHON_VERSION/constraints-*.txt` and
+`files/constraints-PYTHON_VERSION/build-constraints-*.txt` files. You need to check out the right
+'constraints-' branch in a separate repository, and then you can copy, commit and push the generated files.
 
 You need to be a committer, and you have to be authenticated in the apache/airflow repository for your
 git commands to be able to push the new constraints
 
 ```bash
 cd <AIRFLOW_WITH_CONSTRAINTS-MAIN_DIRECTORY>
 git pull
-cp ${AIRFLOW_SOURCES}/files/constraints-*/constraints*.txt .
+cp ${AIRFLOW_SOURCES}/files/constraints-*/{constraints,build-constraints}*.txt .
 git diff
 git add .
 git commit -m "Your commit message here" --no-verify

dev/breeze/doc/09_release_management_tasks.rst

@@ -647,6 +647,12 @@ Generating constraints
 Whenever ``pyproject.toml`` gets modified, the CI main job will re-generate constraint files. Those constraint
 files are stored in separated orphan branches: ``constraints-main``, ``constraints-2-0``.
 
+In addition to runtime constraints, the generation also produces **build constraints** files
+(``build-constraints-PYTHON_VERSION.txt``). Build constraints pin the versions of build-time dependencies
+(e.g. ``setuptools``, ``hatchling``, ``maturin``) for package compilation via build isolation.
+These are published alongside runtime constraints on the same branches, but Airflow installation flows do
+not consume them yet.
+
 Those are constraint files as described in detail in the
 `</contributing-docs/13_airflow_dependencies_and_extras.rst#pinned-constraint-files>`_ contributing documentation.
 

scripts/ci/constraints/ci_commit_constraints.sh

@@ -18,8 +18,9 @@
 cd constraints || exit 1
 git config --local user.email "dev@airflow.apache.org"
 git config --local user.name "Automated GitHub Actions commit"
-git diff --color --exit-code --ignore-matching-lines="^#.*" || \
-git commit --all --message "Updating constraints. GitHub run id:${GITHUB_RUN_ID}
+git add -- 'constraints-*.txt' 'build-constraints-*.txt'
+git diff --cached --color --exit-code --ignore-matching-lines="^#.*" || \
+git commit --message "Updating constraints. GitHub run id:${GITHUB_RUN_ID}
 
 This update in constraints is automatically committed by the CI 'constraints-push' step based on
 '${GITHUB_REF}' in the '${GITHUB_REPOSITORY}' repository with commit sha ${GITHUB_SHA}.

scripts/ci/constraints/ci_diff_constraints.sh

@@ -15,14 +15,17 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-cp -v ./files/constraints-*/constraints*.txt constraints/
+cp -v ./files/constraints-*/{constraints,build-constraints}*.txt constraints/
 cd constraints || exit 1
+git add -- 'constraints-*.txt' 'build-constraints-*.txt'
 
 set +e
-git diff --color --exit-code --ignore-matching-lines="^#.*"
+git diff --cached --color --exit-code --ignore-matching-lines="^#.*"
 diff_status=$?
 set -e
 
+git reset HEAD -- . > /dev/null 2>&1
+
 if [[ ${diff_status} -eq 0 ]]; then
 echo "No changes in constraints"
 elif [[ ${diff_status} -eq 1 ]]; then