Celery AttributeError with importlib's EntryPoint (Fix)

The Fix

pip install celery==5.2.7

Based on closed celery/celery issue #7409 · PR/commit linked

Production note: This usually shows up under retries/timeouts. Treat it as a side-effect risk until you can verify behavior with a canary + real traffic.

Jump to Verify Open PR/Commit

@@ -143,7 +143,7 @@ def gen_task_name(app, name, module_name):
 def load_extension_class_names(namespace):
     for ep in entry_points().get(namespace, []):
-        yield ep.name, ':'.join([ep.module_name, ep.attrs[0]])
+        yield ep.name, ep.value

repro.py

software -> celery:5.2.5 (dawn-chorus) kombu:5.2.4 py:3.10.2
            billiard:3.6.4.0 py-amqp:5.1.0
platform -> system:Darwin arch:64bit
            kernel version:21.4.0 imp:CPython
loader   -> celery.loaders.default.Loader
settings -> transport:amqp results:disabled

deprecated_settings: None

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==5.2.7\nWhen NOT to use: Do not apply this fix if using a version of Celery that does not utilize importlib's EntryPoint.\n\n

Why This Fix Works in Production

Trigger: return self._local.backend
Mechanism: The module_name used in load_extension_class_names was incorrect, causing an AttributeError
Why the fix works: Corrects the module_name used in load_extension_class_names to resolve an AttributeError when using importlib's EntryPoint. (first fixed release: 5.2.7).

Production impact:

If left unfixed, tail latency can spike under load and surface as timeouts/retries (amplifying incident impact).

Why This Breaks in Prod

Shows up under Python 3.10 in real deployments (not just unit tests).
The module_name used in load_extension_class_names was incorrect, causing an AttributeError
Surfaces as: Traceback (most recent call last):

Proof / Evidence

GitHub issue: #7409
Fix PR: https://github.com/celery/celery/pull/7406
First fixed release: 5.2.7
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.37

Discussion

High-signal excerpts from the issue thread (symptoms, repros, edge-cases).

Jump to Sources Open on GitHub

“Hey @shangxiao :wave:, Thank you for opening an issue”

@open-collective-bot · 2022-04-04 · source

“can you try this patch https://github.com/celery/celery/pull/7406 ?”

@auvipy · 2022-04-04 · source

Failure Signature (Search String)

return self._local.backend

Error Message

Stack trace

error.txt

Error Message
-------------
Traceback (most recent call last):
  File "/path/to/project/.direnv/python-3.10.2/lib/python3.10/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 "/path/to/project/django-root/./manage.py", line 20, in <module>
    execute_from_command_line(sys.argv)
  File "/path/to/project/.direnv/python-3.10.2/lib/python3.10/site-packages/django/core/management/__init__.py", line 419, in execute_from_command_line
    utility.execute()
  File "/path/to/project/.direnv/python-3.10.2/lib/python3.10/site-packages/django/core/management/__init__.py", line 413, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/path/to/project/.direnv/python-3.10.2/lib/python3.10/site-packages/django/core/management/base.py", line 354, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/path/to/project/.direnv/python-3.10.2/lib/python3.10/site-packages/django/core/management/base.py", line 398, in execute
    output = self.handle(*args, **options)
  File "/path/to/project/django-root/master_portal_app/management/commands/fetch_and_store_zoho_layout.py", line 15, in handle
    fetch_and_save_dependency_mapping().delay(layout_id=layout.id)
  File "/path/to/proj
... (truncated) ...

Minimal Reproduction

repro.py

software -> celery:5.2.5 (dawn-chorus) kombu:5.2.4 py:3.10.2
            billiard:3.6.4.0 py-amqp:5.1.0
platform -> system:Darwin arch:64bit
            kernel version:21.4.0 imp:CPython
loader   -> celery.loaders.default.Loader
settings -> transport:amqp results:disabled

deprecated_settings: None

Environment

Python: 3.10

What Broke

Users experienced crashes when starting a Celery instance with certain extensions installed.

Why It Broke

The module_name used in load_extension_class_names was incorrect, causing an AttributeError

Fix Options (Details)

Option A — Upgrade to fixed release Safe default (recommended)

pip install celery==5.2.7

When NOT to use: Do not apply this fix if using a version of Celery that does not utilize importlib's EntryPoint.

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/7406

First fixed release: 5.2.7

Last verified: 2026-02-09. Validate in your environment.

When NOT to Use This Fix

Do not apply this fix if using a version of Celery that does not utilize importlib's EntryPoint.

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

Make timeouts explicit and test them (unit + integration) to avoid silent behavior changes.
Instrument retries (attempt count + reason) and alert on spikes to catch dependency slowdowns.

Version Compatibility Table

Version	Status
5.2.7	Fixed

Related Issues

No related fixes found.

Cluster: celery:timeout Celery hub Celery best practices All hubs All clusters

Related clusters: Configuration error Data consistency Duplicates

Sources

We don’t republish the full GitHub discussion text. Use the links above for context.