github: Cache the gnu make tarball

This avoids breaking the build if the gnu download server is
unavailable.

.github/workflows/build.yml

@@ -411,6 +411,16 @@ jobs:
       - uses: actions/download-artifact@v4
         with:
           name: profile
+      - name: Cache downloads
+        id: cache-tarballs
+        uses: actions/cache@v4
+        with:
+          path: /opt/cache
+          key: tarballs-${{ hashFiles('build-make.sh') }}
+      - name: Restore cache
+        if: steps.cache-tarballs.outputs.cache-hit != ''
+        run: |
+          ln -s /opt/cache/*.tar.* .
       - name: Build
         env:
           LLVM_VERSION: ${{needs.prepare.outputs.LLVM_VERSION}}
@@ -427,6 +437,13 @@ jobs:
           NAME=llvm-mingw-$TAG-${{matrix.crt}}-${{matrix.arch}}
           mv llvm-mingw $NAME
           zip -9rq ../$NAME.zip $NAME
+      - name: Save cache
+        if: steps.cache-tarballs.outputs.cache-hit != 'true'
+        run: |
+          mkdir -p /opt/cache
+          for i in make-*.tar.*; do
+              if [ ! -L $i ]; then cp -a $i /opt/cache; fi
+          done
       - uses: actions/upload-artifact@v4
         with:
           name: windows-${{matrix.crt}}-${{matrix.arch}}-toolchain

build-make.sh

@@ -52,7 +52,9 @@ download() {
 }
 
 if [ ! -d make-$MAKE_VERSION ]; then
+    if [ ! -e make-$MAKE_VERSION.tar.gz ]; then
         download https://ftpmirror.gnu.org/gnu/make/make-$MAKE_VERSION.tar.gz
+    fi
     tar -zxf make-$MAKE_VERSION.tar.gz
 fi