Without --worktree/--base the guard fingerprinted the source on every loop, so a loop whose source holds untracked files that change on every job voided each round: test_tier4_e2e scenario 5 keeps the mock herdr's state file (rewritten on each herdr call) in its repository and failed with rc 1 on3fdbb62(passed on7a4a0c2). A loop without sub-delegation now behaves as before (issue #34 requirement 3); with sub-jobs the guard protects against a deadline-closed sub-job still writing. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>