The Fix
Upgrade to version 0.13.0 or later.
Based on closed encode/httpx issue #667 · PR/commit linked
@@ -4,6 +4,32 @@ All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
+## 0.10.0 (December 29th, 2019)
+
+The 0.10.0 release makes some changes that will allow us to support both sync and async interfaces.
fix.md
Option A — Upgrade to fixed release\nUpgrade to version 0.13.0 or later.\nWhen NOT to use: This fix should not be used if backward compatibility is a concern for existing users.\n\n
Why This Fix Works in Production
- Trigger: * [x] We'll need to change `response.next()`. We could *either* underspecify the return type, and allow it to be either sync or async depending on the context,…
- Mechanism: Changes to support both sync and async interfaces required renaming methods for consistency
- Why the fix works: Version 0.10.0 introduces changes to support both sync and async interfaces, including renaming methods for consistency. (first fixed release: 0.13.0).
Why This Breaks in Prod
- Changes to support both sync and async interfaces required renaming methods for consistency
- Production symptom (often without a traceback): * [x] We'll need to change `response.next()`. We could *either* underspecify the return type, and allow it to be either sync or async depending on the context, *or* we use `response.anext()` and `response.next()`. #676
Proof / Evidence
- GitHub issue: #667
- Fix PR: https://github.com/encode/httpx/pull/691
- First fixed release: 0.13.0
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.85
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.66
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“Regarding .aclose() — I think we probably want to switch to that naming for all our other .close() operations too, if only for consistency”
“Milestoned everything that we think is going into this. I thin we prep the release notes *before* we merge, just to give us a final…”
“Pragmatically I think we probably just want to make the response/request changes and document them”
“> If we don’t do that we’ll be blocked from reintroducing the sync API. Yes, that's a good point. Same for Client, then, yes?”
Failure Signature (Search String)
- * [x] We'll need to change `response.next()`. We could *either* underspecify the return type, and allow it to be either sync or async depending on the context, *or* we use
- I assume we want these changes to be backwards-compatible for 0.10, right? (Or should they error on usage?)
Copy-friendly signature
signature.txt
Failure Signature
-----------------
* [x] We'll need to change `response.next()`. We could *either* underspecify the return type, and allow it to be either sync or async depending on the context, *or* we use `response.anext()` and `response.next()`. #676
I assume we want these changes to be backwards-compatible for 0.10, right? (Or should they error on usage?)
Error Message
Signature-only (no traceback captured)
error.txt
Error Message
-------------
* [x] We'll need to change `response.next()`. We could *either* underspecify the return type, and allow it to be either sync or async depending on the context, *or* we use `response.anext()` and `response.next()`. #676
I assume we want these changes to be backwards-compatible for 0.10, right? (Or should they error on usage?)
What Broke
Users faced issues with conditional reads in streaming responses, blocking sync API reintroduction.
Why It Broke
Changes to support both sync and async interfaces required renaming methods for consistency
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
Upgrade to version 0.13.0 or later.
When NOT to use: This fix should not be used if backward compatibility is a concern for existing users.
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/691
First fixed release: 0.13.0
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- This fix should not be used if backward compatibility is a concern for existing users.
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 |
|---|---|
| 0.13.0 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.