More debugging

.github/workflows/build-containers.yml

@@ -43,8 +43,20 @@ jobs:
       - uses: actions/checkout@v2
       - name: Build container for hardcoded arm64v8
         run: |
-          cat /proc/sys/fs/binfmt_misc/qemu-*
-          sudo apt update; sudo apt install docker-buildx-plugin
+          docker run --privileged --rm tonistiigi/binfmt --install all
+          cat /proc/sys/fs/binfmt_misc/qemu-* || true
           cd docker-contributor
           docker build --platform linux/arm64 --build-arg ARCH=arm64v8/ .
 
+  pr-docker-contributor-arm64-buildx:
+    name: PR Docker contributor image (buildx arm64v8)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Build container for hardcoded arm64v8
+        run: |
+          docker run --privileged --rm tonistiigi/binfmt --install all
+          cat /proc/sys/fs/binfmt_misc/qemu-* || true
+          cd docker-contributor
+          docker buildx build --platform linux/arm64 --build-arg ARCH=arm64v8/ .
+