The Fix
pip install celery==5.2.4
Based on closed celery/celery issue #7200 · 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%.
@@ -327,6 +327,10 @@ def worker(ctx, hostname=None, pool_cls=None, app=None, uid=None, gid=None,
if '-D' in argv:
argv.remove('-D')
+ if "--uid" in argv:
+ argv.remove('--uid')
+ if "--gid" in argv:
repro.py
def detach(path, argv, logfile=None, pidfile=None, uid=None,
gid=None, umask=None, workdir=None, fake=False, app=None,
executable=None, hostname=None):
"""Detach program by argv."""
fake = 1 if C_FAKEFORK else fake
# `detached()` will attempt to touch the logfile to confirm that error
# messages won't be lost after detaching stdout/err, but this means we need
# to pre-format it rather than relying on `setup_logging_subsystem()` like
# we can elsewhere.
logfile = node_format(logfile, hostname)
with detached(logfile, pidfile, uid, gid, umask, workdir, fake, after_forkers=False): <<< changes user here
try:
if executable is not None:
path = executable
os.execv(path, [path] + argv) <<< fails here
return EX_OK
except Exception: # pylint: disable=broad-except
if app is None:
from celery import current_app
app = current_app
app.log.setup_logging_subsystem(
'ERROR', logfile, hostname=hostname)
logger.critical("Can't exec %r", ' '.join([path] + argv),
exc_info=True)
return EX_FAILURE
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==5.2.4\nWhen NOT to use: Do not apply this fix if the application requires specific uid/gid handling for security.\n\n
Why This Fix Works in Production
- Trigger: return os.initgroups(username, gid)
- Mechanism: The detach function incorrectly passes uid and gid parameters after changing the process owner
- Why the fix works: Fixes issue #7200 by removing the uid and gid arguments from argv before running in detached mode. (first fixed release: 5.2.4).
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
- The detach function incorrectly passes uid and gid parameters after changing the process owner
- Surfaces as: return os.initgroups(username, gid)
Proof / Evidence
- GitHub issue: #7200
- Fix PR: https://github.com/celery/celery/pull/7244
- First fixed release: 5.2.4
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.85
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.41
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“Hey @ssvasilyev :wave:, Thank you for opening an issue”
Failure Signature (Search String)
- return os.initgroups(username, gid)
Error Message
Stack trace
error.txt
Error Message
-------------
return os.initgroups(username, gid)
OSError: [Errno 1] Operation not permitted
Minimal Reproduction
repro.py
def detach(path, argv, logfile=None, pidfile=None, uid=None,
gid=None, umask=None, workdir=None, fake=False, app=None,
executable=None, hostname=None):
"""Detach program by argv."""
fake = 1 if C_FAKEFORK else fake
# `detached()` will attempt to touch the logfile to confirm that error
# messages won't be lost after detaching stdout/err, but this means we need
# to pre-format it rather than relying on `setup_logging_subsystem()` like
# we can elsewhere.
logfile = node_format(logfile, hostname)
with detached(logfile, pidfile, uid, gid, umask, workdir, fake, after_forkers=False): <<< changes user here
try:
if executable is not None:
path = executable
os.execv(path, [path] + argv) <<< fails here
return EX_OK
except Exception: # pylint: disable=broad-except
if app is None:
from celery import current_app
app = current_app
app.log.setup_logging_subsystem(
'ERROR', logfile, hostname=hostname)
logger.critical("Can't exec %r", ' '.join([path] + argv),
exc_info=True)
return EX_FAILURE
What Broke
Celery fails to start in detached mode, resulting in no logging and process termination.
Why It Broke
The detach function incorrectly passes uid and gid parameters after changing the process owner
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
pip install celery==5.2.4
When NOT to use: Do not apply this fix if the application requires specific uid/gid handling for security.
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)
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/7244
First fixed release: 5.2.4
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- Do not apply this fix if the application requires specific uid/gid handling for security.
- 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 |
|---|---|
| 5.2.4 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.