How to handle Duplicity not being able to do backups to Google Cloud Storage bucket because bucket contains aborted backup

I have setup a Google Cloud Storage bucket for my Duplicity backups. The bucket has a retention policy of 1 year. Today Duplicity got interrupted while doing the backups, and now, every time I want to run a backup, it tries to delete the aborted backup: Attempt of _do_delete Nr. 2 failed. ClientError: An error occurred (AccessDenied) when calling the DeleteObject operation: Access denied. How can I just leave the aborted file stub (can't be deleted due to retention) and let Duplicity start a new backup anyways? ---- ### Workaround if the bucket retention is not locked * Remove bucket retention and let Duplicity have "Storage Object Admin" access to the bucket. * Rerun Duplicity. But I'd prefer a solution that works even if the destination is read only / WORM.