use git log directly

Author: daler

.github/workflows/build-images.yml

@@ -37,15 +37,16 @@ jobs:
           # Display the current environment variables used throughout building
           # -- useful for debugging
           env_var_inventory
+          set -x
+
+          if [[ "$(git log -1 --pretty=%B | head -n 1)" == *"[image skip]"* ]]; then
 
-          if [[ "${{ github.event.head_commit.message }}" == *"[image skip]"* ]]; then
             if tag_exists $BASE_BUSYBOX_IMAGE_NAME latest \
             && tag_exists $BASE_DEBIAN_IMAGE_NAME latest \
             && tag_exists $BUILD_ENV_IMAGE_NAME latest \
             && tag_exists $BOT_IMAGE_NAME latest \
             && tag_exists $ISSUE_RESPONDER_IMAGE_NAME latest \
-            && tag_exists $CREATE_ENV_IMAGE_NAME latest;
-            then
+            && tag_exists $CREATE_ENV_IMAGE_NAME latest; then
               echo "DO_BUILD=false" >> $GITHUB_OUTPUT
             else
               echo "Although '[image skip]' was used in the commit message, no images exist on quay.io to use. So images will be built."