Celery installing celery as pyproject dependency get wrong

The Fix

pip install celery==5.5.3

Based on closed celery/celery issue #9724 · 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

@@ -1 +1 @@
@@ -1 +1 @@
-pymongo==4.10.1
+kombu[mongodb]
diff --git a/requirements/extras/msgpack.txt b/requirements/extras/msgpack.txt

repro.py

$pip install -e .
pip install -e .
Looking in indexes: https://pypi.org/simple, https://pypi.ngc.nvidia.com, https://krisviqi-all:****@gitlab.com/api/v4/projects/20784987/packages/pypi/simple, https://krisviqi-all:****@gitlab.com/api/v4/projects/20715466/packages/pypi/simple, https://krisviqi-all:****@gitlab.com/api/v4/projects/30340519/packages/pypi/simple
Obtaining file:///home/kgk/pyproj
  Installing build dependencies ... done
  Checking if build backend supports build_editable ... done
  Getting requirements to build editable ... done
  Preparing editable metadata (pyproject.toml) ... done
Collecting celery[redis] (from dependencies==1)
  Downloading celery-5.5.2-py3-none-any.whl.metadata (22 kB)
Collecting billiard<5.0,>=4.2.1 (from celery[redis]->dependencies==1)
  Downloading billiard-4.2.1-py3-none-any.whl.metadata (4.4 kB)
Collecting kombu<5.6,>=5.5.2 (from celery[redis]->dependencies==1)
  Downloading kombu-5.5.3-py3-none-any.whl.metadata (3.5 kB)
Collecting vine<6.0,>=5.1.0 (from celery[redis]->dependencies==1)
  Downloading vine-5.1.0-py3-none-any.whl.metadata (2.7 kB)
Collecting click<9.0,>=8.1.2 (from celery[redis]->dependencies==1)
  Downloading click-8.2.1-py3-none-any.whl.metadata (2.5 kB)
Collecting click-didyoumean>=0.3.0 (from celery[redis]->dependencies==1)
  Downloading click_didyoumean-0.3.1-py3-none-any.whl.metadata (3.9 kB)
Collecting click-repl>=0.2.0 (from celery[redis]->dependencies==1)
  Downloading click_repl-0.3.0-py3-none-any.whl.metadata (3.6 kB)
Collecting click-plugins>=1.1.1 (from celery[redis]->dependencies==1)
  Downloading click_plugins-1.1.1-py2.py3-none-any.whl.metadata (6.4 kB)
Collecting python-dateutil>=2.8.2 (from celery[redis]->dependencies==1)
  Downloading python_dateutil-2.9.0.post0-py2.py3-none-any.whl.metadata (8.4 kB)
Collecting redis!=4.5.5,<6.0.0,>=4.5.2 (from celery[redis]->dependencies==1)
  Downloading redis-5.3.0-py3-none-any.whl.metadata (9.2 kB)
Collecting prompt-toolkit>=3.0.36 (from click-repl>=0.2.0->celery[redis]->dependencies==1)
  Downloading prompt_toolkit-3.0.51-py3-none-any.whl.metadata (6.4 kB)
Collecting amqp<6.0.0,>=5.1.1 (from kombu<5.6,>=5.5.2->celery[redis]->dependencies==1)
  Downloading amqp-5.3.1-py3-none-any.whl.metadata (8.9 kB)
Collecting tzdata>=2025.2 (from kombu<5.6,>=5.5.2->celery[redis]->dependencies==1)
  Downloading tzdata-2025.2-py2.py3-none-any.whl.metadata (1.4 kB)
Collecting six>=1.5 (from python-dateutil>=2.8.2->celery[redis]->dependencies==1)
  Downloading six-1.17.0-py2.py3-none-any.whl.metadata (1.7 kB)
Collecting PyJWT~=2.9.0 (from redis!=4.5.5,<6.0.0,>=4.5.2->celery[redis]->dependencies==1)
  Downloading PyJWT-2.9.0-py3-none-any.whl.metadata (3.0 kB)
Collecting async-timeout>=4.0.3 (from redis!=4.5.5,<6.0.0,>=4.5.2->celery[redis]->dependencies==1)
  Downloading async_timeout-5.0.1-py3-none-any.whl.metadata (5.1 kB)
Collecting wcwidth (from prompt-toolkit>=3.0.36->click-repl>=0.2.0->celery[redis]->dependencies==1)
  Downloading wcwidth-0.2.13-py2.py3-none-any.whl.metadata (14 kB)
Downloading billiard-4.2.1-py3-none-any.whl (86 kB)
Downloading click-8.2.1-py3-none-any.whl (102 kB)
Downloading click_didyoumean-0.3.1-py3-none-any.whl (3.6 kB)
Downloading click_plugins-1.1.1-py2.py3-none-any.whl (7.5 kB)
Downloading click_repl-0.3.0-py3-none-any.whl (10 kB)
Downloading kombu-5.5.3-py3-none-any.whl (209 kB)
Downloading vine-5.1.0-py3-none-any.whl (9.6 kB)
Downloading python_dateutil-2.9.0.post0-py2.py3-none-any.whl (229 kB)
Downloading redis-5.3.0-py3-none-any.whl (272 kB)
Downloading celery-5.5.2-py3-none-any.whl (438 kB)
Downloading amqp-5.3
... (truncated) ...

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==5.5.3\nWhen NOT to use: Do not use this fix if the application relies on specific Redis versions.\n\n

Why This Fix Works in Production

Trigger: - [X ] I have included all related issues and possible duplicate issues
Mechanism: The installation of Celery was incorrectly pulling Redis dependencies instead of Kombu dependencies
Why the fix works: Allows Celery to install from Kombu dependencies for better alignment, addressing the issue with incorrect Redis installation. (first fixed release: 5.5.3).

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 3.11 in real deployments (not just unit tests).
The installation of Celery was incorrectly pulling Redis dependencies instead of Kombu dependencies
Production symptom (often without a traceback): - [X ] I have included all related issues and possible duplicate issues

Proof / Evidence

GitHub issue: #9724
Fix PR: https://github.com/celery/celery/pull/9696
First fixed release: 5.5.3
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.95
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.44

Discussion

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

Jump to Sources Open on GitHub

“I think it is the same as https://github.com/celery/celery/issues/9680 which got solved by https://github.com/celery/celery/pull/9696 and should be in 5.5.3”

@woutdenolf · 2025-06-18 · source

“I think we need a new release to fix this. but not sure if it is fixed already or not?”

@auvipy · 2025-05-27 · source

Failure Signature (Search String)

- [X ] I have included all related issues and possible duplicate issues
or possible duplicates to this issue as requested by the checklist above.

Copy-friendly signature

signature.txt

Failure Signature
-----------------
- [X ] I have included all related issues and possible duplicate issues
or possible duplicates to this issue as requested by the checklist above.

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
- [X ] I have included all related issues and possible duplicate issues
or possible duplicates to this issue as requested by the checklist above.

Minimal Reproduction

repro.py

$pip install -e .
pip install -e .
Looking in indexes: https://pypi.org/simple, https://pypi.ngc.nvidia.com, https://krisviqi-all:****@gitlab.com/api/v4/projects/20784987/packages/pypi/simple, https://krisviqi-all:****@gitlab.com/api/v4/projects/20715466/packages/pypi/simple, https://krisviqi-all:****@gitlab.com/api/v4/projects/30340519/packages/pypi/simple
Obtaining file:///home/kgk/pyproj
  Installing build dependencies ... done
  Checking if build backend supports build_editable ... done
  Getting requirements to build editable ... done
  Preparing editable metadata (pyproject.toml) ... done
Collecting celery[redis] (from dependencies==1)
  Downloading celery-5.5.2-py3-none-any.whl.metadata (22 kB)
Collecting billiard<5.0,>=4.2.1 (from celery[redis]->dependencies==1)
  Downloading billiard-4.2.1-py3-none-any.whl.metadata (4.4 kB)
Collecting kombu<5.6,>=5.5.2 (from celery[redis]->dependencies==1)
  Downloading kombu-5.5.3-py3-none-any.whl.metadata (3.5 kB)
Collecting vine<6.0,>=5.1.0 (from celery[redis]->dependencies==1)
  Downloading vine-5.1.0-py3-none-any.whl.metadata (2.7 kB)
Collecting click<9.0,>=8.1.2 (from celery[redis]->dependencies==1)
  Downloading click-8.2.1-py3-none-any.whl.metadata (2.5 kB)
Collecting click-didyoumean>=0.3.0 (from celery[redis]->dependencies==1)
  Downloading click_didyoumean-0.3.1-py3-none-any.whl.metadata (3.9 kB)
Collecting click-repl>=0.2.0 (from celery[redis]->dependencies==1)
  Downloading click_repl-0.3.0-py3-none-any.whl.metadata (3.6 kB)
Collecting click-plugins>=1.1.1 (from celery[redis]->dependencies==1)
  Downloading click_plugins-1.1.1-py2.py3-none-any.whl.metadata (6.4 kB)
Collecting python-dateutil>=2.8.2 (from celery[redis]->dependencies==1)
  Downloading python_dateutil-2.9.0.post0-py2.py3-none-any.whl.metadata (8.4 kB)
Collecting redis!=4.5.5,<6.0.0,>=4.5.2 (from celery[redis]->dependencies==1)
  Downloading redis-5.3.0-py3-none-any.whl.metadata (9.2 kB)
Collecting prompt-toolkit>=3.0.36 (from click-repl>=0.2.0->celery[redis]->dependencies==1)
  Downloading prompt_toolkit-3.0.51-py3-none-any.whl.metadata (6.4 kB)
Collecting amqp<6.0.0,>=5.1.1 (from kombu<5.6,>=5.5.2->celery[redis]->dependencies==1)
  Downloading amqp-5.3.1-py3-none-any.whl.metadata (8.9 kB)
Collecting tzdata>=2025.2 (from kombu<5.6,>=5.5.2->celery[redis]->dependencies==1)
  Downloading tzdata-2025.2-py2.py3-none-any.whl.metadata (1.4 kB)
Collecting six>=1.5 (from python-dateutil>=2.8.2->celery[redis]->dependencies==1)
  Downloading six-1.17.0-py2.py3-none-any.whl.metadata (1.7 kB)
Collecting PyJWT~=2.9.0 (from redis!=4.5.5,<6.0.0,>=4.5.2->celery[redis]->dependencies==1)
  Downloading PyJWT-2.9.0-py3-none-any.whl.metadata (3.0 kB)
Collecting async-timeout>=4.0.3 (from redis!=4.5.5,<6.0.0,>=4.5.2->celery[redis]->dependencies==1)
  Downloading async_timeout-5.0.1-py3-none-any.whl.metadata (5.1 kB)
Collecting wcwidth (from prompt-toolkit>=3.0.36->click-repl>=0.2.0->celery[redis]->dependencies==1)
  Downloading wcwidth-0.2.13-py2.py3-none-any.whl.metadata (14 kB)
Downloading billiard-4.2.1-py3-none-any.whl (86 kB)
Downloading click-8.2.1-py3-none-any.whl (102 kB)
Downloading click_didyoumean-0.3.1-py3-none-any.whl (3.6 kB)
Downloading click_plugins-1.1.1-py2.py3-none-any.whl (7.5 kB)
Downloading click_repl-0.3.0-py3-none-any.whl (10 kB)
Downloading kombu-5.5.3-py3-none-any.whl (209 kB)
Downloading vine-5.1.0-py3-none-any.whl (9.6 kB)
Downloading python_dateutil-2.9.0.post0-py2.py3-none-any.whl (229 kB)
Downloading redis-5.3.0-py3-none-any.whl (272 kB)
Downloading celery-5.5.2-py3-none-any.whl (438 kB)
Downloading amqp-5.3
... (truncated) ...

Environment

Python: 3.11

What Broke

Users experienced incorrect Redis installations when installing Celery as a dependency.

Why It Broke

The installation of Celery was incorrectly pulling Redis dependencies instead of Kombu dependencies

Fix Options (Details)

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

pip install celery==5.5.3

When NOT to use: Do not use this fix if the application relies on specific Redis versions.

Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.

Option D — Guard side-effects with OnceOnly Guardrail for side-effects

Mitigate duplicate external side-effects under retries/timeouts/agent loops by gating the operation before calling external systems.

Place OnceOnly between your code/agent and real side-effects (Stripe, emails, CRM, APIs).
Use a stable key per side-effect (e.g., customer_id + action + idempotency_key).
Fail-safe: configure fail-open vs fail-closed based on blast radius and spend risk.

Show example snippet (optional)

onceonly.py

from onceonly import OnceOnly
import os

once = OnceOnly(api_key=os.environ["ONCEONLY_API_KEY"], fail_open=True)

# Stable idempotency key per real side-effect.
# Use a request id / job id / webhook delivery id / Stripe event id, etc.
event_id = "evt_..."  # replace
key = f"stripe:webhook:{event_id}"

res = once.check_lock(key=key, ttl=3600)
if res.duplicate:
    return {"status": "already_processed"}

# Safe to execute the side-effect exactly once.
handle_event(event_id)

See OnceOnly SDK

When NOT to use: Do not use this to hide logic bugs or data corruption. Use it to block duplicate external side-effects and enforce tool permissions/spend caps.

Fix reference: https://github.com/celery/celery/pull/9696

First fixed release: 5.5.3

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

When NOT to Use This Fix

Do not use this fix if the application relies on specific Redis versions.
Do not use this to hide logic bugs or data corruption. Use it to block duplicate external side-effects and enforce tool permissions/spend caps.

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
5.5.3	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 installing celery as pyproject dependency get wrong redis (Fix)