Celery Docs seem to suggest that ignore

The Fix

pip install celery==5.2.4

Based on closed celery/celery issue #7203 · 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.

Open PR/Commit

@@ -1641,7 +1641,7 @@ setting.
 
 Results can be enabled/disabled on a per-execution basis, by passing the ``ignore_result`` boolean parameter,
-when calling ``apply_async`` or ``delay``.
+when calling ``apply_async``.

fix.md

Option A — Upgrade to fixed release\npip install celery==5.2.4\nWhen NOT to use: This fix is not applicable if using delay with ignore_result.\n\n

Why This Fix Works in Production

Trigger: TypeError: mytask() got an unexpected keyword argument 'ignore_result'
Mechanism: Documentation incorrectly suggested that ignore_result can be used with delay
Why the fix works: Updated documentation to clarify that the `ignore_result` parameter can only be used with `apply_async`, not with `delay`. (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

Documentation incorrectly suggested that ignore_result can be used with delay
Surfaces as: TypeError: mytask() got an unexpected keyword argument 'ignore_result'

Proof / Evidence

GitHub issue: #7203
Fix PR: https://github.com/celery/celery/pull/7209
First fixed release: 5.2.4
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.95
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.79

Discussion

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

Jump to Sources Open on GitHub

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

@open-collective-bot · 2022-01-04 · source

“> You're right”

@auvipy · 2022-01-06 · source

Failure Signature (Search String)

TypeError: mytask() got an unexpected keyword argument 'ignore_result'

Error Message

Stack trace

error.txt

Error Message
-------------
TypeError: mytask() got an unexpected keyword argument 'ignore_result'

What Broke

Users experienced TypeError when passing ignore_result to delay.

Why It Broke

Documentation incorrectly suggested that ignore_result can be used with delay

Fix Options (Details)

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

pip install celery==5.2.4

When NOT to use: This fix is not applicable if using delay with ignore_result.

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/7209

First fixed release: 5.2.4

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

When NOT to Use This Fix

This fix is not applicable if using delay with ignore_result.
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.

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.

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 Docs seem to suggest that ignore_result can be set on `delay` (Fix)