Celery Autodiscovery fails for empty "related

The Fix

pip install celery==4.4.0rc5

Based on closed celery/celery issue #4810 · 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%.

Open PR/Commit

@@ -655,7 +655,8 @@ def autodiscover_tasks(self, packages=None,
             related_name (str): The name of the module to find.  Defaults
                 to "tasks": meaning "look for 'module.tasks' for every
-                module in ``packages``."
+                module in ``packages``.".  If ``None`` will only try to import
+                the package, i.e. "look for 'module'".

fix.md

Option A — Upgrade to fixed release\npip install celery==4.4.0rc5\nWhen NOT to use: Do not use this fix if you require strict related_name suffixes for task discovery.\n\n

Why This Fix Works in Production

Trigger: Autodiscovery fails for empty "related_name"
Mechanism: The autodiscover_tasks function fails with a KeyError when related_name is empty
Why the fix works: Allows passing 'related_name=None' for autodiscovery, enabling the import of the plain package without a specific suffix. (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 autodiscover_tasks function fails with a KeyError when related_name is empty
Production symptom (often without a traceback): Autodiscovery fails for empty "related_name"

Proof / Evidence

GitHub issue: #4810
Fix PR: https://github.com/celery/celery/pull/4813
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: 0.71

Discussion

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

Jump to Sources Open on GitHub

“This seems to boil down to a Python 2.7 vs 3.x issue”

@lnielsen · 2018-06-13 · source

“I've already opened https://github.com/celery/celery/pull/4813”

@slint · 2018-08-12 · source

Failure Signature (Search String)

Autodiscovery fails for empty "related_name"

Copy-friendly signature

signature.txt

Failure Signature
-----------------
Autodiscovery fails for empty "related_name"

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
Autodiscovery fails for empty "related_name"

Environment

Python: 2.7

What Broke

Users experience KeyError when attempting to autodiscover tasks with an empty related_name.

Why It Broke

The autodiscover_tasks function fails with a KeyError when related_name is empty

Fix Options (Details)

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

pip install celery==4.4.0rc5

When NOT to use: Do not use this fix if you require strict related_name suffixes for 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/4813

First fixed release: 4.4.0rc5

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

When NOT to Use This Fix

Do not use this fix if you require strict related_name suffixes for task discovery.

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.

Cluster: celery:configuration-error Celery hub Celery best practices All hubs All clusters

Related clusters: Data consistency Duplicates Duplicate processing

Sources

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

Celery Autodiscovery fails for empty "related_name" (Fix)