django celery error: Unrecoverable error: AttributeError("'EntryPoint' object has no attribute 'module_name'")

Question

I am perplexed,from a weird error which i have no idea as i am new to celery, this error occurs on just the setup phase, every thing is simply configured as written in the celery doc https://docs.celeryq.dev/en/stable/django/first-steps-with-django.html the tracback is:

(env) muhammad@huzaifa:~/Desktop/practice/app$ celery -A app worker -l INFO
[2022-04-04 16:21:40,988: WARNING/MainProcess] No hostname was supplied. Reverting to default 'localhost'
[2022-04-04 16:21:40,993: CRITICAL/MainProcess] Unrecoverable error: AttributeError("'EntryPoint' object has no attribute 'module_name'")
Traceback (most recent call last):
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/app/base.py", line 1250, in backend
    return self._local.backend
AttributeError: '_thread._local' object has no attribute 'backend'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/worker/worker.py", line 203, in start
    self.blueprint.start(self)
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/bootsteps.py", line 112, in start
    self.on_start()
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/apps/worker.py", line 136, in on_start
    self.emit_banner()
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/apps/worker.py", line 170, in emit_banner
    ' \n', self.startup_info(artlines=not use_image))),
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/apps/worker.py", line 232, in startup_info
    results=self.app.backend.as_uri(),
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/app/base.py", line 1252, in backend
    self._local.backend = new_backend = self._get_backend()
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/app/base.py", line 955, in _get_backend
    backend, url = backends.by_url(
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/app/backends.py", line 69, in by_url
    return by_name(backend, loader), url
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/app/backends.py", line 47, in by_name
    aliases.update(load_extension_class_names(extension_namespace))
  File "/home/muhammad/Desktop/practice/env/lib/python3.8/site-packages/celery/utils/imports.py", line 146, in load_extension_class_names
    yield ep.name, ':'.join([ep.module_name, ep.attrs[0]])
AttributeError: 'EntryPoint' object has no attribute 'module_name'

the init file is:

from __future__ import absolute_import, unicode_literals

from .celery import app as celery_app

__all__ = ('celery_app',)

celery.py:

import os

from celery import Celery

# Set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'app.settings')

app = Celery('app', broker='localhost')

# Using a string here means the worker doesn't have to serialize
# the configuration object to child processes.
# - namespace='CELERY' means all celery-related configuration keys
#   should have a `CELERY_` prefix.
app.config_from_object('django.conf:settings', namespace='CELERY')

# Load task modules from all registered Django apps.
app.autodiscover_tasks()


@app.task(bind=True)
def debug_task(self):
    print(f'Request: {self.request!r}')

For your information, rabbitmq-server is running on localhost thats why i have set BROKER_URL TO 'localhost'

 rabbitmq-server.service - RabbitMQ Messaging Server
     Loaded: loaded (/lib/systemd/system/rabbitmq-server.service; enabled; vendor preset: enabled)
     Active: active (running) since Sun 2022-04-03 16:14:04 PKT; 24h ago
   Main PID: 1005 (beam.smp)
     Status: "Initialized"
      Tasks: 91 (limit: 9090)

idk why this is happening, i have been look around for like hours and cant find a solution and not even the error on google or anywhere. any help would be greatly appreciated Thanks!

Answer 1

You are encountering a new bug with celery, reported here: https://github.com/celery/celery/issues/7409

The workaround you can try is to pin the versions of your dependency for celery to an older version (ie before release of the celery bug). For instance, my requirements.txt includes:

celery==5.2.3

or on the command line you might just be able to run

pip install celery==5.2.3

(For reference, the versions where I was seeing the error reported here were celery 5.2.5 & click 8.1.2)

Hopefully this gets fixed upstream and we can remove our version pins.

Answer 2

Encountered the same error downgraded the celery version to 5.2.0 and it worked

Answer 3

I downgrade celery to 5.2.3 and everything work fine again.

Thank you @Jeff-G

Answer 4

I encountered the same problem today. So, I just Downgraded the celery version to 5.2.3

pip install celery==5.2.3

and it worked