The Fix
Upgrade to version 0.17.0 or later.
Based on closed encode/httpx issue #1479 · 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%.
@@ -17,7 +17,7 @@ HTTPX is a fully featured HTTP client for Python 3, which provides sync and asyn
**Note**: _HTTPX should be considered in beta. We believe we've got the public API to
a stable point now, but would strongly recommend pinning your dependencies to the `0.16.*`
-release, so that you're able to properly review [API changes between package updates](https://github.com/encode/httpx/blob/master/CHANGELOG.md). A 1.0 release is expected to be issued sometime in late 2020._
+release, so that you're able to properly review [API changes between package updates](https://github.com/encode/httpx/blob/master/CHANGELOG.md). A 1.0 release is expected to be issued sometime in 2021._
Option A — Upgrade to fixed release\nUpgrade to version 0.17.0 or later.\nWhen NOT to use: This fix is not applicable if the README is not the source of the issue.\n\n
Why This Fix Works in Production
- Trigger: Users were misinformed about the release timeline, leading to confusion.
- Mechanism: Updated the README to reflect the new estimate for the v1.0 release.
- Why the fix works: Updated the README to reflect the new estimate for the v1.0 release. (first fixed release: 0.17.0).
- 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
- Production symptom (often without a traceback): Users were misinformed about the release timeline, leading to confusion.
Proof / Evidence
- GitHub issue: #1479
- Fix PR: https://github.com/encode/httpx/pull/1445
- First fixed release: 0.17.0
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.85
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.55
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“This was already updated, just hasn't been included in a release yet. https://github.com/encode/httpx/pull/1445”
“Sure, the docs will update on our next release.”
“> already updated Ah, I knew I had already seen this brought up! 😄”
Failure Signature (Search String)
- Users were misinformed about the release timeline, leading to confusion.
Copy-friendly signature
Failure Signature
-----------------
Users were misinformed about the release timeline, leading to confusion.
Error Message
Signature-only (no traceback captured)
Error Message
-------------
Users were misinformed about the release timeline, leading to confusion.
What Broke
Users were misinformed about the release timeline, leading to confusion.
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
Upgrade to version 0.17.0 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/1445
First fixed release: 0.17.0
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- This fix is not applicable if the README is not the source of the issue.
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.
- Add a TLS smoke test that performs a real handshake in CI (include CA bundle validation and hostname checks).
- Alert on handshake failures by error string and endpoint to catch cert/CA changes quickly.
Version Compatibility Table
| Version | Status |
|---|---|
| 0.17.0 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.