bot: Allow None cache_root (it is unused by the crontrigger command)

Author: marco-c

bot/code_coverage_bot/hooks/base.py

@@ -49,8 +49,9 @@ def __init__(
             "Mercurial setup", repository=self.repository, revision=self.revision
         )
 
-        assert os.path.isdir(cache_root), f"Cache root {cache_root} is not a dir."
-        self.repo_dir = os.path.join(cache_root, self.branch)
+        if cache_root is not None:
+            assert os.path.isdir(cache_root), f"Cache root {cache_root} is not a dir."
+            self.repo_dir = os.path.join(cache_root, self.branch)
 
         # Load coverage tasks for all platforms
         decision_task_id = taskcluster.get_decision_task(self.branch, self.revision)

bot/code_coverage_bot/hooks/crontrigger.py

@@ -51,5 +51,5 @@ def run(self) -> None:
 def main() -> None:
     logger.info("Starting code coverage bot for crontrigger")
     args = setup_cli(ask_revision=False, ask_repository=False)
-    hook = CronTriggerHook(args.task_name_filter, args.cache_root, args.working_dir)
+    hook = CronTriggerHook(args.task_name_filter, None, args.working_dir)
     hook.run()