When a Celery task fails, `result.ready()` evaluates to `True` but `result.successful()` is `False`.
Calling `result.get()` without `propagate=False` on a failed task will re-raise the task's exception, causing the Flask endpoint to crash with a 500 Internal Server Error instead of returning the task's failed status.
Additionally, if `result.result` is an Exception object, returning it directly in the dictionary will cause a `TypeError` during JSON serialization.
Affected files: views.py
Signed-off-by: Tang Vu <vuminhtang2212@gmail.com>
Reverts commit 4d69165ab6. Now that a
release has this option, it's ok to show it in the docs. It had been
reverted because the 2.2.x docs showed it before 2.2.3 was released.
