cache mxe builds (#41472)

.github/workflows/mxe.yml

@@ -29,14 +29,58 @@ on:
 jobs:
   build:
 
+    env:
+      CCACHE_DIR: ${{ github.workspace }}/.ccache
+
     runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v2
+
+    - name: Build Dockerfile
+      run: |
+        cd ms-windows/mxe
+        docker build -f mxe.Dockerfile --tag mxe-qt5-builder:current .
+
+    - name: Prepare build cache for pull request
+      uses: pat-s/always-upload-cache@v2.1.3
+      if: github.event_name == 'pull_request'
+      with:
+        path: ${{ github.workspace }}/.ccache
+        key: mxe-ccache-${{ github.actor }}-${{ github.head_ref }}-${{ github.sha }}
+        # The head_ref or source branch of the pull request in a workflow run.
+        # The base_ref or target branch of the pull request in a workflow run.
+        restore-keys: |
+          mxe-ccache-${{ github.actor }}-${{ github.head_ref }}-
+          mxe-ccache-${{ github.base_ref }}-
+          mxe-ccache-refs/heads/master-
+
+    - name: Prepare build cache for branch/tag
+      # use a fork of actions/cache@v2 to upload cache even when the build or test failed
+      uses: pat-s/always-upload-cache@v2.1.3
+      if: github.event_name != 'pull_request'
+      with:
+        path: ${{ github.workspace }}/.ccache
+        # The branch or tag ref that triggered the workflow run. For branches this in the format refs/heads/<branch_name>, and for tags it is refs/tags/<tag_name>
+        key: mxe-ccache-${{ github.ref }}-${{ github.sha }}
+        restore-keys: |
+          mxe-ccache-${{ github.ref }}-
+          mxe-ccache-refs/heads/master-
+
     - name: Cross build with MXE
-      run: cd $GITHUB_WORKSPACE && ms-windows/mxe/build.sh
+      run: |
+        mkdir -p ${{ github.workspace }}/.ccache
+        docker run -v ${GITHUB_WORKSPACE}:/root/QGIS \
+            -w /root/QGIS  \
+            --env CCACHE_DIR=/root/QGIS/.ccache \
+            mxe-qt5-builder:current \
+            /root/QGIS/ms-windows/mxe/build-mxe.sh
+
     - name: Rename artifact
-      run: cd $GITHUB_WORKSPACE && mv qgis-mxe-release-*.zip qgis-mxe-release.zip
+      run: |
+        cd $GITHUB_WORKSPACE
+        mv qgis-mxe-release-*.zip qgis-mxe-release.zip
+
     - name: Upload build
       uses: actions/upload-artifact@v2.2.2
       with:

ms-windows/mxe/build-mxe.sh

@@ -50,9 +50,6 @@ TARGET=x86_64-w64-mingw32.shared
 # Set base path for all tools
 export PATH=${PATH}:${MXE}/usr/bin
 
-# Fix CCACHE directory
-export CCACHE_DIR=${PWD}/.ccache
-
 if [ ! -e ${CCACHE_DIR} ]; then
   mkdir -p ${CCACHE_DIR}
 fi
@@ -73,9 +70,12 @@ cd ${BUILD_DIR}
 
 if [[ "$COMMAND" != *"package"* ]]; then
 
+    echo "::group::compile QGIS"
+
     ${MXE}/usr/bin/${TARGET}-cmake .. \
         -DCMAKE_BUILD_TYPE=RelWithDebugInfo \
         -DCMAKE_INSTALL_PREFIX=${RELEASE_DIR} \
+        -DUSE_CCACHE=ON \
         -DENABLE_TESTS=OFF \
         -DWITH_QSPATIALITE=ON \
         -DWITH_APIDOC=OFF \
@@ -90,8 +90,15 @@ if [[ "$COMMAND" != *"package"* ]]; then
 
     make -j16 install
 
+    echo "::endgroup::"
+
+    #echo "ccache statistics"
+    ccache -s
+
 fi
 
+echo "::group::package"
+
 # Collect deps
 
 $PYDEPLOY --build=${RELEASE_DIR} --objdump=${MXE}/usr/bin/${TARGET}-objdump ${RELEASE_DIR}/qgis.exe
@@ -108,7 +115,6 @@ __TXT__
 
 # First cleanup
 rm -rf ${BUILD_DIR}
-rm -rf ${CCACHE_DIR}
 
 # Make the zip
 
@@ -119,6 +125,8 @@ zip -r -m ${ZIP_NAME} $(basename ${RELEASE_DIR})
 # Second cleanup
 rm -rf ${RELEASE_DIR}
 
+echo "::endgroup::"
+
 popd
 
 echo "Release in $ZIP_NAME ready."

ms-windows/mxe/mxe.Dockerfile

@@ -10,7 +10,8 @@ RUN DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
     software-properties-common \
     lsb-release \
     gpg-agent \
-    python3-distutils
+    python3-distutils \
+    ccache
 
 RUN apt-key adv \
     --keyserver keyserver.ubuntu.com \