Celery CLI help output: avoid click text rewrapping (Fix)

The Fix

pip install celery==5.3.0rc1

Based on closed celery/celery issue #8151 · 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

@@ -300,8 +300,11 @@ def worker(ctx, hostname=None, pool_cls=None, app=None, uid=None, gid=None,
     """Start worker instance.
 
+    \b
     Examples
     --------

repro.py

Usage: celery worker [OPTIONS]

  Start worker instance.

  Examples
  --------

  $ celery --app=proj worker -l INFO $ celery -A proj worker -l INFO -Q
  hipri,lopri $ celery -A proj worker --concurrency=4 $ celery -A proj worker
  --concurrency=1000 -P eventlet $ celery worker --autoscale=10,0

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==5.3.0rc1\nWhen NOT to use: This fix should not be applied if the CLI output format is intentionally designed to wrap text.\n\n

Why This Fix Works in Production

Trigger: - [x] I have included all related issues and possible duplicate issues in this issue
Mechanism: The CLI help output was improperly formatted due to text rewrapping by the click library
Why the fix works: Avoids text rewrapping in the CLI help output for the celery worker command. (first fixed release: 5.3.0rc1).

Production impact:

If left unfixed, retries/timeouts can trigger duplicate external side-effects (double charges, duplicate emails, repeated writes).

Why This Breaks in Prod

The CLI help output was improperly formatted due to text rewrapping by the click library
Production symptom (often without a traceback): - [x] I have included all related issues and possible duplicate issues in this issue

Proof / Evidence

GitHub issue: #8151
Fix PR: https://github.com/celery/celery/pull/8152
First fixed release: 5.3.0rc1
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.66

Discussion

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

Jump to Sources Open on GitHub

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

@open-collective-bot · 2023-03-23 · source

Failure Signature (Search String)

- [x] I have included all related issues and possible duplicate issues in this issue

Copy-friendly signature

signature.txt

Failure Signature
-----------------
- [x] I have included all related issues and possible duplicate issues in this issue

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
- [x] I have included all related issues and possible duplicate issues in this issue

Minimal Reproduction

repro.py

Usage: celery worker [OPTIONS]

  Start worker instance.

  Examples
  --------

  $ celery --app=proj worker -l INFO $ celery -A proj worker -l INFO -Q
  hipri,lopri $ celery -A proj worker --concurrency=4 $ celery -A proj worker
  --concurrency=1000 -P eventlet $ celery worker --autoscale=10,0

What Broke

Users experienced confusion due to poorly formatted help output in the CLI.

Why It Broke

The CLI help output was improperly formatted due to text rewrapping by the click library

Fix Options (Details)

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

pip install celery==5.3.0rc1

When NOT to use: This fix should not be applied if the CLI output format is intentionally designed to wrap text.

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/8152

First fixed release: 5.3.0rc1

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

When NOT to Use This Fix

This fix should not be applied if the CLI output format is intentionally designed to wrap text.

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
5.3.0rc1	Fixed

Related Issues

No related fixes found.

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

Related clusters: Configuration error Data consistency Duplicate processing

Sources

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