.github/workflows/docker.yml: Interrupt the build before it gets canceled at 6 hours

Author: Matthias Koeppe

.github/workflows/docker.yml

@@ -78,6 +78,10 @@ on:
       free_disk_space:
         default: false
         type: boolean
+      timeout:
+        description: 'Elapsed time (seconds) at which to kill the build'
+        default: 20000
+        type: number
       #
       # Publishing to GitHub Packages
       #
@@ -224,6 +228,7 @@ jobs:
         if: inputs.free_disk_space
       - name: Configure and build Sage distribution within a Docker container
         run: |
+          (sleep ${{ inputs.timeout }}; for id in $(docker ps -q); do docker exec $id pkill make; done) &
           set -o pipefail; EXTRA_DOCKER_BUILD_ARGS="--build-arg NUMPROC=4 --build-arg USE_MAKEFLAGS=\"-k V=0 SAGE_NUM_THREADS=3\"" tox -e $TOX_ENV -- $TARGETS 2>&1 | sed "/^configure: notice:/s|^|::warning file=artifacts/$LOGS_ARTIFACT_NAME/config.log::|;/^configure: warning:/s|^|::warning file=artifacts/$LOGS_ARTIFACT_NAME/config.log::|;/^configure: error:/s|^|::error file=artifacts/$LOGS_ARTIFACT_NAME/config.log::|;"
       - name: Copy logs from the Docker image or build container
         run: |