django-celery-email error "Received unregistered task of type 'djcelery_email_send'."

[espenak]

Traceback

[2013-11-12 09:53:14,495: INFO/MainProcess] consumer: Connected to amqp://devilry@127.0.0.1:5672/devilryhost.
[2013-11-12 09:55:09,065: ERROR/MainProcess] Received unregistered task of type 'djcelery_email_send'.
The message has been ignored and discarded.

Did you remember to import the module containing this task?
Or maybe you are using relative imports?
More: http://docs.celeryq.org/en/latest/userguide/tasks.html#names

The full contents of the message body was:
{'utc': True, 'chord': None, 'args': (<django.core.mail.message.EmailMessage object at 0x12d08450>,), 'retries': 0, 'expires': None, 'task': 'djcelery_email_send', 'callbacks': None, 'errbacks': None, 'taskset': None, 'kwargs': {'_backend_init_kwargs': {'username': None, 'password': None}}, 'eta': None, 'id': '96445c40-e97c-45b6-afba-cbf6dd8e79e6'} (1132b)
Traceback (most recent call last):
  File "/ifi/asgard/p00/devilry/devilrybuild/buildoutcache/eggs/celery-3.0.13-py2.7.egg/celery/worker/consumer.py", line 435, in on_task_received
    strategies[name](message, body, message.ack_log_error)
KeyError: ‘djcelery_email_send'

Workaround

Do not use django-celery-email.

[espenak]

The fix

This is simply a bug in the migration guide. We forgot to include that:

INSTALLED_APPS += ['djcelery_email']

Must be included in the settings-file.

[espenak]

How to debug similar problems (for developers)

Uncomment the For testing sections under Celery in src/devilry_developer/devilry_developer/settings/base.py and comment out CELERY_ALWAYS_EAGER=True to actually send Celery tasks to the Celery worker.

Run the celery worker with:

$ bin/django_dev.py celery worker --no-execv --loglevel=debug

We have a test-task in src/devilry_developer/devilry_developer/tasks.py that you can test using the shell:

$ bin/django_dev.py shell
>>> from devilry_developer.tasks import add 
>>> add.delay(2, 2)

It should produce some output from the celery worker.