Celery 5.1.2: test suite uses outdated `case` module (Fix)

The Fix

pip install celery==5.2.1

Based on closed celery/celery issue #6958 · 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%.

Jump to Verify Open PR/Commit

@@ -2,15 +2,11 @@
 from datetime import datetime, timedelta
 from typing import Any, Mapping, Sequence
+from unittest.mock import Mock
 
 from celery import Celery

repro.py

+ /usr/bin/pytest -ra --ignore=t/unit/backends/test_s3.py --ignore=t/unit/backends/test_mongodb.py --ignore=t/distro/test_CI_reqs.py
=========================================================================== test session starts ============================================================================
platform linux -- Python 3.8.12, pytest-6.2.5, py-1.10.0, pluggy-0.13.1
benchmark: 3.4.1 (defaults: timer=time.perf_counter disable_gc=False min_rounds=5 min_time=0.000005 max_time=1.0 calibration_precision=10 warmup=False warmup_iterations=100000)
Using --randomly-seed=4261956870
rootdir: /home/tkloczko/rpmbuild/BUILD/celery-5.1.2, configfile: pytest.ini
plugins: forked-1.3.0, shutil-1.7.0, virtualenv-1.7.0, expect-1.1.0, flake8-1.0.7, timeout-1.4.2, betamax-0.8.1, freezegun-0.4.2, aspectlib-1.5.2, toolbox-0.5, rerunfailures-9.1.1, requests-mock-1.9.3, cov-2.12.1, flaky-3.7.0, benchmark-3.4.1, xdist-2.3.0, pylama-7.7.1, datadir-1.3.1, regressions-2.2.0, cases-3.6.3, xprocess-0.18.1, black-0.3.12, asyncio-0.15.1, subtests-0.5.0, isort-2.0.0, hypothesis-6.14.6, mock-3.6.1, profiling-1.7.0, randomly-3.8.0, nose2pytest-1.0.8, pyfakefs-4.5.1, tornado-0.8.1, twisted-1.13.3, aiohttp-0.3.0, localserver-0.5.0, anyio-3.3.1, trio-0.7.0, Faker-8.12.2
collected 0 items / 1 error

================================================================================== ERRORS ==================================================================================
______________________________________________________________________ ERROR collecting test session _______________________________________________________________________
/usr/lib64/python3.8/importlib/__init__.py:127: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
<frozen importlib._bootstrap>:1014: in _gcd_import
    ???
<frozen importlib._bootstrap>:991: in _find_and_load
    ???
<frozen importlib._bootstrap>:975: in _find_and_load_unlocked
    ???
<frozen importlib._bootstrap>:671: in _load_unlocked
    ???
/usr/lib/python3.8/site-packages/_pytest/assertion/rewrite.py:170: in exec_module
    exec(co, module.__dict__)
t/unit/conftest.py:10: in <module>
    from case.utils import decorator
E   ModuleNotFoundError: No module named 'case'
========================================================================= short test summary info ==========================================================================
ERROR  - ModuleNotFoundError: No module named 'case'
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
============================================================================= 1 error in 0.57s =============================================================================
pytest-xprocess reminder::Be sure to terminate the started process by running 'pytest --xkill' if you have not explicitly done so in your fixture with 'xprocess.getinfo(<process_name>).terminate()'.

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==5.2.1\nWhen NOT to use: This fix is not applicable if the `case` module is still required for other tests.\n\n

Why This Fix Works in Production

Trigger: collected 0 items / 1 error
Mechanism: The test suite relies on the outdated `case` module, which is no longer maintained
Why the fix works: Removes the dependency on the outdated `case` module, addressing the issue of test failures due to missing modules. (first fixed release: 5.2.1).

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 3.8.12 in real deployments (not just unit tests).
The test suite relies on the outdated `case` module, which is no longer maintained
Production symptom (often without a traceback): collected 0 items / 1 error

Proof / Evidence

GitHub issue: #6958
Fix PR: https://github.com/celery/celery/pull/7077
First fixed release: 5.2.1
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.95
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.39

Discussion

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

Jump to Sources Open on GitHub

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

@open-collective-bot · 2021-09-16 · source

Failure Signature (Search String)

collected 0 items / 1 error
================================================================================== ERRORS ==================================================================================

Copy-friendly signature

signature.txt

Failure Signature
-----------------
collected 0 items / 1 error
================================================================================== ERRORS ==================================================================================

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
collected 0 items / 1 error
================================================================================== ERRORS ==================================================================================

Minimal Reproduction

repro.py

+ /usr/bin/pytest -ra --ignore=t/unit/backends/test_s3.py --ignore=t/unit/backends/test_mongodb.py --ignore=t/distro/test_CI_reqs.py
=========================================================================== test session starts ============================================================================
platform linux -- Python 3.8.12, pytest-6.2.5, py-1.10.0, pluggy-0.13.1
benchmark: 3.4.1 (defaults: timer=time.perf_counter disable_gc=False min_rounds=5 min_time=0.000005 max_time=1.0 calibration_precision=10 warmup=False warmup_iterations=100000)
Using --randomly-seed=4261956870
rootdir: /home/tkloczko/rpmbuild/BUILD/celery-5.1.2, configfile: pytest.ini
plugins: forked-1.3.0, shutil-1.7.0, virtualenv-1.7.0, expect-1.1.0, flake8-1.0.7, timeout-1.4.2, betamax-0.8.1, freezegun-0.4.2, aspectlib-1.5.2, toolbox-0.5, rerunfailures-9.1.1, requests-mock-1.9.3, cov-2.12.1, flaky-3.7.0, benchmark-3.4.1, xdist-2.3.0, pylama-7.7.1, datadir-1.3.1, regressions-2.2.0, cases-3.6.3, xprocess-0.18.1, black-0.3.12, asyncio-0.15.1, subtests-0.5.0, isort-2.0.0, hypothesis-6.14.6, mock-3.6.1, profiling-1.7.0, randomly-3.8.0, nose2pytest-1.0.8, pyfakefs-4.5.1, tornado-0.8.1, twisted-1.13.3, aiohttp-0.3.0, localserver-0.5.0, anyio-3.3.1, trio-0.7.0, Faker-8.12.2
collected 0 items / 1 error

================================================================================== ERRORS ==================================================================================
______________________________________________________________________ ERROR collecting test session _______________________________________________________________________
/usr/lib64/python3.8/importlib/__init__.py:127: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
<frozen importlib._bootstrap>:1014: in _gcd_import
    ???
<frozen importlib._bootstrap>:991: in _find_and_load
    ???
<frozen importlib._bootstrap>:975: in _find_and_load_unlocked
    ???
<frozen importlib._bootstrap>:671: in _load_unlocked
    ???
/usr/lib/python3.8/site-packages/_pytest/assertion/rewrite.py:170: in exec_module
    exec(co, module.__dict__)
t/unit/conftest.py:10: in <module>
    from case.utils import decorator
E   ModuleNotFoundError: No module named 'case'
========================================================================= short test summary info ==========================================================================
ERROR  - ModuleNotFoundError: No module named 'case'
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
============================================================================= 1 error in 0.57s =============================================================================
pytest-xprocess reminder::Be sure to terminate the started process by running 'pytest --xkill' if you have not explicitly done so in your fixture with 'xprocess.getinfo(<process_name>).terminate()'.

Environment

Python: 3.8.12

What Broke

Test suite fails to run due to missing `case` module, causing CI pipeline failures.

Why It Broke

The test suite relies on the outdated `case` module, which is no longer maintained

Fix Options (Details)

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

pip install celery==5.2.1

When NOT to use: This fix is not applicable if the `case` module is still required for other tests.

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/7077

First fixed release: 5.2.1

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

When NOT to Use This Fix

This fix is not applicable if the `case` module is still required for other tests.

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
5.2.1	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.