Serialize HW tests

test/match_changed_files.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+#
+# Usage: $0 PATTERN
+# If files in the last commit match PATTERN, exit 0. Else, exit 1
+#
+# Usage in github actions:
+#  <job_name>:
+#    runs-on: ubuntu-latest
+#    steps:
+#    - uses: actions/checkout@v3
+#      with: { fetch-depth: 2 }         # Important for git diff to work
+#    - run: if ./match_changed_files.sh '.*' ; then echo RUN=1 >> $GITHUB_ENV ; fi
+#    - if: ${{ env.RUN == 1 }}
+#      run: echo yohoo!
+
+CHANGED_FILES=`git --no-pager diff --name-only HEAD~1 HEAD | xargs`
+echo "Pattern: [$1], files: $CHANGED_FILES"
+for FILE in $CHANGED_FILES; do [[ "$FILE" =~ $1 ]] && exit 0; done
+exit 1