The Fix
pip install celery==4.4.0rc5
Based on closed celery/celery issue #4699 · PR/commit linked
Production note: Most teams hit this during upgrades or environment changes. Roll out with a canary and smoke critical endpoints (health, OpenAPI/docs) before 100%.
@@ -37,6 +37,28 @@ def _make_id(target): # pragma: no cover
+def _boundmethod_safe_weakref(obj):
+ """Get weakref constructor appropriate for `obj`. `obj` may be a bound method.
+
repro.py
Thanks!!
I have fixed the problem by import the models only in the tasks and allow the auto discover task to find in the whole application instead of installed apps section.
Thank you
I have fixed the problem by import the models only in the tasks and allow the auto discover task to find in the whole application instead of installed apps section.
Thank you
Please attach the code or provide reference because I'm facing the same issue
> I have fixed the problem by import the models only in the tasks and allow the auto discover task to find in the whole application instead of installed apps section.
> Thank you
Please attach the code or provide reference because I'm facing the same issue
Don't use:
verify
Re-run the minimal reproduction on your broken version, then apply the fix and re-run.
fix.md
Option A — Upgrade to fixed release\npip install celery==4.4.0rc5\nWhen NOT to use: This fix is not applicable if the application structure does not allow for proper task discovery.\n\n
Why This Fix Works in Production
- Trigger: ... (truncated) ...
- Mechanism: The error occurs when Django apps are not fully loaded before Celery tries to access them
- Why the fix works: Addresses the issue of 'django.core.exceptions.AppRegistryNotReady' by implementing a patch that may fix the problem. (first fixed release: 4.4.0rc5).
Production impact:
- If left unfixed, the same config can fail only in production (env differences), causing startup failures or partial feature outages.
Why This Breaks in Prod
- Shows up under Python 2.7 in real deployments (not just unit tests).
- The error occurs when Django apps are not fully loaded before Celery tries to access them
- Surfaces as: File "/proj.env/bin/celery", line 11, in <module>\n sys.exit(main())\n File "/proj.env/lib/python2.7/site-packages/celery/__main__.py", line 16, in main\n _main()\n File…
Proof / Evidence
- GitHub issue: #4699
- Fix PR: https://github.com/celery/celery/pull/4719
- First fixed release: 4.4.0rc5
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.85
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.35
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“Same exception for env: Python: 3.6.5 Django: 2.0.5 Without any celery-beat | celery-results. RC2 works fine.”
“Hi, @jonashaag I have the same issue here”
“> > I have fixed the problem by import the models only in the tasks and allow the auto discover task to find in the…”
“Same problem. Config is similar to friendka.”
Failure Signature (Search String)
- ... (truncated) ...
Error Message
Stack trace
error.txt
Error Message
-------------
File "/proj.env/bin/celery", line 11, in <module>\n sys.exit(main())\n File "/proj.env/lib/python2.7/site-packages/celery/__main__.py", line 16, in main\n _main()\n File "/proj.env/lib/python2.7/site-packages/celery/bin/celery.py", line 322, in main\n cmd.execute_from_commandline(argv)\n File "/proj.env/lib/python2.7/site-packages/celery/bin/celery.py", line 484, in execute_from_commandline\n super(CeleryCommand, self).execute_from_commandline(argv)))\n File "/proj.env/lib/python2.7/site-packages/celery/bin/base.py", line 275, in execute_from_commandline\n return self.handle_argv(self.prog_name, argv[1:])\n File "/proj.env/lib/python2.7/site-packages/celery/bin/celery.py", line 476, in handle_argv\n return self.execute(command, argv)\n File "/proj.env/lib/python2.7/site-packages/celery/bin/celery.py", line 408, in execute\n ).run_from_argv(self.prog_name, argv[1:], command=argv[0])\n File "/proj.env/lib/python2.7/site-packages/celery/bin/worker.py", line 223, in run_from_argv\n return self(*args, **options)\n File "/proj.env/lib/python2.7/site-packages/celery/bin/base.py", line 238, in __call__\n ret = self.run(*args, **kwargs)\n File "/proj.env/lib/python2.7/site-packages/celery/bin/worker.py", line 257, in run\n **kwargs)\n File "/proj.env/lib/python2.7/site-packages/celery/worker/worker.py", line 96, in __init__\n self.app.loader.in
... (truncated) ...
Minimal Reproduction
repro.py
Thanks!!
I have fixed the problem by import the models only in the tasks and allow the auto discover task to find in the whole application instead of installed apps section.
Thank you
I have fixed the problem by import the models only in the tasks and allow the auto discover task to find in the whole application instead of installed apps section.
Thank you
Please attach the code or provide reference because I'm facing the same issue
> I have fixed the problem by import the models only in the tasks and allow the auto discover task to find in the whole application instead of installed apps section.
> Thank you
Please attach the code or provide reference because I'm facing the same issue
Don't use:
Environment
- Python: 2.7
What Broke
Celery worker fails to start, causing task scheduling to halt.
Why It Broke
The error occurs when Django apps are not fully loaded before Celery tries to access them
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
pip install celery==4.4.0rc5
When NOT to use: This fix is not applicable if the application structure does not allow for proper task discovery.
Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.
Fix reference: https://github.com/celery/celery/pull/4719
First fixed release: 4.4.0rc5
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- This fix is not applicable if the application structure does not allow for proper task discovery.
Verify Fix
verify
Re-run the minimal reproduction on your broken version, then apply the fix and re-run.
Did This Fix Work in Your Case?
Quick signal helps us prioritize which fixes to verify and improve.
Prevention
- Capture the exact failing error string in logs and tests so you can reproduce via a minimal script.
- Pin production dependencies and upgrade only with a reproducible test that hits the failing path.
Version Compatibility Table
| Version | Status |
|---|---|
| 4.4.0rc5 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.