ci: Make arm64 persistent workers work

.cirrus.yml

@@ -50,21 +50,19 @@ cat_logs_snippet: &CAT_LOGS
       - env
 
 linux_arm64_container_snippet: &LINUX_ARM64_CONTAINER
-  dockerfile: ci/linux-debian.Dockerfile
-  # Reduce number of CPUs to be able to do more builds in parallel.
-  cpu: 1
-  # Gives us more CPUs for free if they're available.
-  greedy: true
-  # More than enough for our scripts.
-  memory: 2G
+  env_script:
+    - env | tee /tmp/env
+  build_script:
+    - DOCKER_BUILDKIT=1 docker build --file "ci/linux-debian.Dockerfile" --tag="ci_secp256k1_arm"
+    - docker image prune --force  # Cleanup stale layers
+  test_script:
+    - docker run --rm --mount "type=bind,src=./,dst=/ci_secp256k1" --env-file /tmp/env --replace --name "ci_secp256k1_arm" "ci_secp256k1_arm" bash -c "cd /ci_secp256k1/ && ./ci/ci.sh"
 
 task:
   name: "ARM64: Linux (Debian stable)"
-  arm_container:
-    << : *LINUX_ARM64_CONTAINER
   persistent_worker:
     labels:
-      type: arm64  
+      type: arm64
   env:
     ECDH: yes
     RECOVERY: yes
@@ -73,17 +71,14 @@ task:
   matrix:
      # Currently only gcc-snapshot, the other compilers are tested on GHA with QEMU
      - env: { CC: 'gcc-snapshot' }
-  test_script:
-    - ./ci/ci.sh
+  << : *LINUX_ARM64_CONTAINER
   << : *CAT_LOGS
 
 task:
   name: "ARM64: Linux (Debian stable), Valgrind"
-  arm_container:
-    << : *LINUX_ARM64_CONTAINER
   persistent_worker:
     labels:
-      type: arm64  
+      type: arm64
   env:
     ECDH: yes
     RECOVERY: yes
@@ -96,6 +91,5 @@ task:
      - env: { CC: 'clang' }
      - env: { CC: 'gcc-snapshot' }
      - env: { CC: 'clang-snapshot' }
-  test_script:
-    - ./ci/ci.sh
+  << : *LINUX_ARM64_CONTAINER
   << : *CAT_LOGS

ci/linux-debian.Dockerfile

@@ -29,11 +29,14 @@ RUN apt-get update && apt-get install --no-install-recommends -y \
         gcc-i686-linux-gnu libc6-dev-i386-cross libc6-dbg:i386 libubsan1:i386 libasan8:i386 \
         gcc-s390x-linux-gnu libc6-dev-s390x-cross libc6-dbg:s390x \
         gcc-arm-linux-gnueabihf libc6-dev-armhf-cross libc6-dbg:armhf \
-        gcc-aarch64-linux-gnu libc6-dev-arm64-cross libc6-dbg:arm64 \
         gcc-powerpc64le-linux-gnu libc6-dev-ppc64el-cross libc6-dbg:ppc64el \
         gcc-mingw-w64-x86-64-win32 wine64 wine \
         gcc-mingw-w64-i686-win32 wine32 \
-        python3
+        python3 && \
+        if ! ( dpkg --print-architecture | grep --quiet "arm64" ) ; then \
+         apt-get install --no-install-recommends -y \
+         gcc-aarch64-linux-gnu libc6-dev-arm64-cross libc6-dbg:arm64 ;\
+        fi
 
 # Build and install gcc snapshot
 ARG GCC_SNAPSHOT_MAJOR=14
@@ -44,7 +47,7 @@ RUN apt-get update && apt-get install --no-install-recommends -y wget libgmp-dev
     sha512sum --check --ignore-missing sha512.sum && \
     # We should have downloaded exactly one tar.xz file
     ls && \
-    [[ $(ls *.tar.xz | wc -l) -eq "1" ]] && \
+    [ $(ls *.tar.xz | wc -l) -eq "1" ] && \
     tar xf *.tar.xz && \
     mkdir gcc-build && cd gcc-build && \
     ../*/configure --prefix=/opt/gcc-snapshot --enable-languages=c --disable-bootstrap --disable-multilib --without-isl && \