The script already rm-s the staged file before running the user command, so the success-path delete_file was a wasted round-trip, and post-cancel deletes ran against a stopped sandbox. Only delete on kill() when the file was uploaded but exec was never dispatched (checked under the env lock, bounded request_timeout); exec_fn skips dispatch once cancelled. Co-authored-by: JoaoMarcos44 <joaomarcosdias444@gmail.com>