The Fix
Upgrade to version 0.18.2 or later.
Based on closed encode/httpx issue #1686 · 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%.
@@ -897,32 +897,35 @@ def _send_handling_auth(
) -> Response:
auth_flow = auth.sync_auth_flow(request)
- request = next(auth_flow)
+ try:
+ request = next(auth_flow)
Option A — Upgrade to fixed release\nUpgrade to version 0.18.2 or later.\nWhen NOT to use: Do not apply this fix if your CI environment does not support treating warnings as errors.\n\n
Why This Fix Works in Production
- Trigger: Switch CI to treat warnings as errors
- Mechanism: CI was not configured to treat deprecation warnings as errors, leading to potential regressions
- Why the fix works: Treats warnings as errors in the CI, ensuring that deprecation warnings are addressed upfront. (first fixed release: 0.18.2).
- 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 3.10 in real deployments (not just unit tests).
- CI was not configured to treat deprecation warnings as errors, leading to potential regressions
- Production symptom (often without a traceback): Switch CI to treat warnings as errors
Proof / Evidence
- GitHub issue: #1686
- Fix PR: https://github.com/encode/httpx/pull/1687
- First fixed release: 0.18.2
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.75
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.76
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“Prompted by #1670 Since merging #1682 we're now including test runs for Python 3.10 beta. Issue #1670 notes that we've got a deprecation warning being raised on 3.10. The sensible approach in terms of *process* here is to make sure that our”
Failure Signature (Search String)
- Switch CI to treat warnings as errors
- So first step here prior to considering #1670 should be to upgrade our warnings to errors.
Copy-friendly signature
Failure Signature
-----------------
Switch CI to treat warnings as errors
So first step here prior to considering #1670 should be to upgrade our warnings to errors.
Error Message
Signature-only (no traceback captured)
Error Message
-------------
Switch CI to treat warnings as errors
So first step here prior to considering #1670 should be to upgrade our warnings to errors.
Environment
- Python: 3.10
What Broke
Deprecation warnings were not caught during CI, risking unnoticed regressions.
Why It Broke
CI was not configured to treat deprecation warnings as errors, leading to potential regressions
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
Upgrade to version 0.18.2 or later.
Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.
Fix reference: https://github.com/encode/httpx/pull/1687
First fixed release: 0.18.2
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- Do not apply this fix if your CI environment does not support treating warnings as errors.
Did This Fix Work in Your Case?
Quick signal helps us prioritize which fixes to verify and improve.
Prevention
- Add a CI check that diffs key outputs after upgrades (OpenAPI schema snapshots, JSON payload shapes, CLI output).
- Upgrade behind a canary and run integration tests against the canary before 100% rollout.
Version Compatibility Table
| Version | Status |
|---|---|
| 0.18.2 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.