bpo-45695: Test out-of-tree builds on GHA

tiran · tiran · commit 165b4fe90256 · 2021-12-04T10:29:07.000+01:00
The Ubuntu test runner now configures and compiles CPython out of tree.
The source directory is a read-only bind mount to ensure that the build
cannot create or modify any files in the source tree.

For testing the source directory is re-mounted writable. 15 test modules
depend on writable sources and lack of .pyc files slows CI down.

Signed-off-by: Christian Heimes &lt;christian@python.org&gt;
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -179,13 +179,28 @@ jobs:
         echo "PATH=/usr/lib/ccache:$PATH" >> $GITHUB_ENV
     - name: Configure ccache action
       uses: hendrikmuhs/ccache-action@v1
-    - name: Configure CPython
-      run: ./configure --with-pydebug --with-openssl=$OPENSSL_DIR
-    - name: Build CPython
+    - name: Setup directory envs for out-of-tree builds
+      run: |
+        echo "CPYTHON_RO_SRCDIR=$(realpath -m ${GITHUB_WORKSPACE}/../cpython-ro-srcdir)" >> $GITHUB_ENV
+        echo "CPYTHON_BUILDDIR=$(realpath -m ${GITHUB_WORKSPACE}/../cpython-builddir)" >> $GITHUB_ENV
+    - name: Create directories for read-only out-of-tree builds
+      run: mkdir -p $CPYTHON_RO_SRCDIR $CPYTHON_BUILDDIR
+    - name: Bind mount sources read-only
+      run: sudo mount --bind -o ro $GITHUB_WORKSPACE $CPYTHON_RO_SRCDIR
+    - name: Configure CPython out-of-tree
+      working-directory: ${{ env.CPYTHON_BUILDDIR }}
+      run: ../cpython-ro-srcdir/configure --with-pydebug --with-openssl=$OPENSSL_DIR
+    - name: Build CPython out-of-tree
+      working-directory: ${{ env.CPYTHON_BUILDDIR }}
       run: make -j4
     - name: Display build info
+      working-directory: ${{ env.CPYTHON_BUILDDIR }}
       run: make pythoninfo
+    - name: Remount sources writable for tests
+      # some tests write to srcdir, lack of pyc files slows down testing
+      run: sudo mount $CPYTHON_RO_SRCDIR -oremount,rw
     - name: Tests
+      working-directory: ${{ env.CPYTHON_BUILDDIR }}
       run: xvfb-run make buildbottest TESTOPTS="-j4 -uall,-cpu"
 
   build_ubuntu_ssltests:
diff --git a/Misc/NEWS.d/next/Tests/2021-12-03-14-19-16.bpo-45695.QKBn2E.rst b/Misc/NEWS.d/next/Tests/2021-12-03-14-19-16.bpo-45695.QKBn2E.rst
@@ -0,0 +1,3 @@
+The Ubuntu test runner now configures and compiles CPython out of tree. The
+source directory is a read-only bind mount to ensure that the build cannot
+create or modify any files in the source tree.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+The Ubuntu test runner now configures and compiles CPython out of tree. The`
	`2`	`+source directory is a read-only bind mount to ensure that the build cannot`
	`3`	`+create or modify any files in the source tree.`