Passing task_cls to Celery replaces the Django fixup's default DjangoTask, so FileMoveScopedTask, built on the plain Task, left every task without delay_on_commit. The workflow AI suggestions trigger failed with an AttributeError.
FileMoveScopedTask now subclasses DjangoTask, which only needs django.db.transaction and is safe to import before apps load. The task scope test also asserts tasks are DjangoTask instances.
Tasks such as bulk_update_documents moved a document's files once for its manual post_save and again for every save its workflows made, each time taking the global media lock.
All tasks now run through FileMoveScopedTask, which opens a file move scope around the task body, including when the task raises. bulk_update_documents flushes after each document so long bulk edits still make steady progress.
stumpylog
shamoon
Trenton Holmes