Merge bitcoin/bitcoin#31428: ci: Allow build dir on CI host

8888ee4 ci: Allow build dir on CI host (MarcoFalke)

Pull request description:

  This is required to pass cross builds on to a different machine after the build.

  See for example bitcoin/bitcoin#31176, but this pull will also allow someone to implement it outside this repo.

ACKs for top commit:
  davidgumberg:
    lgtm ACK bitcoin/bitcoin@8888ee4
  hebasto:
    re-ACK 8888ee4.

Tree-SHA512: a1e2c32bc1b95efbd0b48287ac5b49e0e1bacbf5a5800845be5352bbdd3e17fa478e90348b2e94e95cf3ae863cdf75ab444089376588f6f8eec438f73a4b5b97

.github/workflows/ci.yml

@@ -270,16 +270,16 @@ jobs:
     timeout-minutes: 120
     env:
       FILE_ENV: "./ci/test/00_setup_env_native_asan.sh"
-      DANGER_CI_ON_HOST_CACHE_FOLDERS: 1
+      DANGER_CI_ON_HOST_FOLDERS: 1
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Set Ccache directory
-        run: echo "CCACHE_DIR=${RUNNER_TEMP}/ccache_dir" >> "$GITHUB_ENV"
-
-      - name: Set base root directory
-        run: echo "BASE_ROOT_DIR=${RUNNER_TEMP}" >> "$GITHUB_ENV"
+      - name: Set CI directories
+        run: |
+          echo "CCACHE_DIR=${{ runner.temp }}/ccache_dir" >> "$GITHUB_ENV"
+          echo "BASE_ROOT_DIR=${{ runner.temp }}" >> "$GITHUB_ENV"
+          echo "BASE_BUILD_DIR=${{ runner.temp }}/build-asan" >> "$GITHUB_ENV"
 
       - name: Restore Ccache cache
         id: ccache-cache

ci/test/02_run_container.sh

@@ -78,18 +78,21 @@ if [ -z "$DANGER_RUN_CI_ON_HOST" ]; then
   CI_DEPENDS_MOUNT="type=volume,src=${CONTAINER_NAME}_depends,dst=$DEPENDS_DIR/built"
   CI_DEPENDS_SOURCES_MOUNT="type=volume,src=${CONTAINER_NAME}_depends_sources,dst=$DEPENDS_DIR/sources"
   CI_PREVIOUS_RELEASES_MOUNT="type=volume,src=${CONTAINER_NAME}_previous_releases,dst=$PREVIOUS_RELEASES_DIR"
+  CI_BUILD_MOUNT=""
 
-  if [ "$DANGER_CI_ON_HOST_CACHE_FOLDERS" ]; then
+  if [ "$DANGER_CI_ON_HOST_FOLDERS" ]; then
     # ensure the directories exist
     mkdir -p "${CCACHE_DIR}"
     mkdir -p "${DEPENDS_DIR}/built"
     mkdir -p "${DEPENDS_DIR}/sources"
     mkdir -p "${PREVIOUS_RELEASES_DIR}"
+    mkdir -p "${BASE_BUILD_DIR}"  # Unset by default, must be defined externally
 
     CI_CCACHE_MOUNT="type=bind,src=${CCACHE_DIR},dst=$CCACHE_DIR"
     CI_DEPENDS_MOUNT="type=bind,src=${DEPENDS_DIR}/built,dst=$DEPENDS_DIR/built"
     CI_DEPENDS_SOURCES_MOUNT="type=bind,src=${DEPENDS_DIR}/sources,dst=$DEPENDS_DIR/sources"
     CI_PREVIOUS_RELEASES_MOUNT="type=bind,src=${PREVIOUS_RELEASES_DIR},dst=$PREVIOUS_RELEASES_DIR"
+    CI_BUILD_MOUNT="--mount type=bind,src=${BASE_BUILD_DIR},dst=${BASE_BUILD_DIR}"
   fi
 
   if [ "$DANGER_CI_ON_HOST_CCACHE_FOLDER" ]; then
@@ -131,6 +134,7 @@ if [ -z "$DANGER_RUN_CI_ON_HOST" ]; then
                   --mount "${CI_DEPENDS_MOUNT}" \
                   --mount "${CI_DEPENDS_SOURCES_MOUNT}" \
                   --mount "${CI_PREVIOUS_RELEASES_MOUNT}" \
+                  ${CI_BUILD_MOUNT} \
                   --env-file /tmp/env-$USER-$CONTAINER_NAME \
                   --name "$CONTAINER_NAME" \
                   --network ci-ip6net \