Intentionally fail a job (to make sure that finalize thus also fails)

.github/workflows/pr_checks.yml

@@ -186,6 +186,7 @@ jobs:
         run: |
           make clean
           make cleanall
+      - run: exit 1 # TODO: delete this line when finished debugging.
   stalecheck-npm-install:
     # In this job, we are basically trying to check if `package-lock.json` is in
     # sync with `package-lock.json`.