The Fix
pip install urllib3==1.25
Based on closed urllib3/urllib3 issue #1498 · PR/commit linked
@@ -1,28 +1,40 @@
@@ -1,28 +1,40 @@
language: python
-script:
- - ./_travis/run.sh
+sudo: false
Option A — Upgrade to fixed release\npip install urllib3==1.25\nWhen NOT to use: This fix should not be applied if integration tests are not required for your deployment process.\n\n
Why This Fix Works in Production
- Trigger: - [ ] Allow testing against versions of Python before and after significant changes were introduced:
- Mechanism: The release process lacked integration tests, which are essential for ensuring compatibility across various environments
- Why the fix works: Revises the release process to include integration tests in addition to unit tests, addressing the need for an integration testbed as outlined in issue #1498. (first fixed release: 1.25).
Why This Breaks in Prod
- Shows up under Python 2.7.8 in real deployments (not just unit tests).
- The release process lacked integration tests, which are essential for ensuring compatibility across various environments
- Production symptom (often without a traceback): - [ ] Allow testing against versions of Python before and after significant changes were introduced:
Proof / Evidence
- GitHub issue: #1498
- Fix PR: https://github.com/urllib3/urllib3/pull/1508
- First fixed release: 1.25
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.95
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.87
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“This issue is being used as a brain dump for me until I create the new repository for this work. This work would be done as part of #1392. - [ ] Allow testing against versions of Python before and after significant changes were introduced:”
Failure Signature (Search String)
- - [ ] Allow testing against versions of Python before and after significant changes were introduced:
- - Python 2.7.8 / 2.7.9 for SSLContext
Copy-friendly signature
Failure Signature
-----------------
- [ ] Allow testing against versions of Python before and after significant changes were introduced:
- Python 2.7.8 / 2.7.9 for SSLContext
Error Message
Signature-only (no traceback captured)
Error Message
-------------
- [ ] Allow testing against versions of Python before and after significant changes were introduced:
- Python 2.7.8 / 2.7.9 for SSLContext
Environment
- Python: 2.7.8
What Broke
Integration tests were missing, leading to potential undetected issues in production environments.
Why It Broke
The release process lacked integration tests, which are essential for ensuring compatibility across various environments
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
pip install urllib3==1.25
Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.
Fix reference: https://github.com/urllib3/urllib3/pull/1508
First fixed release: 1.25
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- This fix should not be applied if integration tests are not required for your deployment process.
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 |
|---|---|
| 1.25 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.