Celery Missing dependency on future in 4.4.4 (Fix)

The Fix

pip install celery==4.4.5

Based on closed celery/celery issue #6145 · 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

@@ -1,4 +1,5 @@
 pytz>dev
 billiard>=3.6.3.0,<4.0
+future>=0.18.0
 kombu>=4.6.10,<4.7
 vine==1.3.0

repro.py

weblate_1   |   File "/usr/local/lib/python3.7/dist-packages/celery/backends/redis.py", line 25, in <module>
weblate_1   |     from .base import BaseKeyValueStoreBackend
weblate_1   |   File "/usr/local/lib/python3.7/dist-packages/celery/backends/base.py", line 10, in <module>
weblate_1   |     from future.utils import raise_with_traceback
weblate_1   | ModuleNotFoundError: No module named 'future'

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==4.4.5\nWhen NOT to use: This fix is not applicable if the 'future' library is already included in the requirements.\n\n

Why This Fix Works in Production

Trigger: Missing dependency on future in 4.4.4
Mechanism: Missing dependency on the 'future' library in the requirements file
Why the fix works: Adds a missing dependency on the 'future' library in the requirements file, addressing issue #6145. (first fixed release: 4.4.5).

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 3.7 in real deployments (not just unit tests).
Missing dependency on the 'future' library in the requirements file
Production symptom (often without a traceback): Missing dependency on future in 4.4.4

Proof / Evidence

GitHub issue: #6145
Fix PR: https://github.com/celery/celery/pull/6146
First fixed release: 4.4.5
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.75
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.64

Discussion

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

Jump to Sources Open on GitHub

“Here it comes: https://github.com/celery/celery/pull/6146”

@nijel · 2020-06-03 · source

Failure Signature (Search String)

Missing dependency on future in 4.4.4
- [x] I have included all related issues and possible duplicate issues

Copy-friendly signature

signature.txt

Failure Signature
-----------------
Missing dependency on future in 4.4.4
- [x] I have included all related issues and possible duplicate issues

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
Missing dependency on future in 4.4.4
- [x] I have included all related issues and possible duplicate issues

Minimal Reproduction

repro.py

weblate_1   |   File "/usr/local/lib/python3.7/dist-packages/celery/backends/redis.py", line 25, in <module>
weblate_1   |     from .base import BaseKeyValueStoreBackend
weblate_1   |   File "/usr/local/lib/python3.7/dist-packages/celery/backends/base.py", line 10, in <module>
weblate_1   |     from future.utils import raise_with_traceback
weblate_1   | ModuleNotFoundError: No module named 'future'

Environment

Python: 3.7

What Broke

Users may experience import errors due to the missing 'future' dependency.

Why It Broke

Missing dependency on the 'future' library in the requirements file

Fix Options (Details)

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

pip install celery==4.4.5

When NOT to use: This fix is not applicable if the 'future' library is already included in the requirements.

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/6146

First fixed release: 4.4.5

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

When NOT to Use This Fix

This fix is not applicable if the 'future' library is already included in the requirements.

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
4.4.5	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.