urllib3 Python 3.11.0 alpha 7 times out in CI (Fix)

The Fix

pip install urllib3==1.26.10

Based on closed urllib3/urllib3 issue #2602 · PR/commit linked

Jump to Verify Open PR/Commit

@@ -57,7 +57,7 @@ jobs:
             experimental: false
             nox-session: test-3.9
-          - python-version: 3.11-dev
+          - python-version: 3.11.0-beta.3
             os: ubuntu-latest

repro.py

#!/bin/bash

set -exo pipefail

make clean
./configure
make
./python -m ensurepip
./python -m pip install ~/urllib3
./python -m pip install -r ~/urllib3/dev-requirements.txt
timeout 15 ./python -m pytest ~/urllib3/test/with_dummyserver/test_proxy_poolmanager.py::TestHTTPProxyManager

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

fix.md

Option A — Upgrade to fixed release\npip install urllib3==1.26.10\nWhen NOT to use: Do not use if it changes public behavior or if the failure cannot be reproduced.\n\n

Why This Fix Works in Production

Trigger: Thu, 14 Apr 2022 10:28:23 GMT nox > python -m OpenSSL.debug
Mechanism: Updates the coverage version to 6.4 to support Python 3.11, addressing issues with pytest in the CI.
Why the fix works: Updates the coverage version to 6.4 to support Python 3.11, addressing issues with pytest in the CI. (first fixed release: 1.26.10).

Why This Breaks in Prod

Triggered by an upgrade/regression window: 1.1.1 breaks; 1.26.10 is the first fixed release.
Shows up under Python 3.11.0 in real deployments (not just unit tests).
Production symptom (often without a traceback): Thu, 14 Apr 2022 10:28:23 GMT nox > python -m OpenSSL.debug

Proof / Evidence

GitHub issue: #2602
Fix PR: https://github.com/urllib3/urllib3/pull/2620
First fixed release: 1.26.10
Affected versions: 1.1.1
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.95
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.68

Discussion

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

Jump to Sources Open on GitHub

“Currently running a git bisect on CPython with the following to see if I find any hints:”

@sethmlarson · 2022-06-01 · source

“Thanks! To be clear what I've seen on CI was not hanging, just everything was slow. Bumping the timeout to 30mn would allow tests to…”

@pquentin · 2022-06-01 · source

“I actually tried this last night funny enough, and 30 minutes does not fix the issue. It hangs on this test indefinitely and won't progress…”

@nateprewitt · 2022-06-01 · source

“Closed in https://github.com/urllib3/urllib3/pull/2620”

@sethmlarson · 2022-06-02 · source

Failure Signature (Search String)

Thu, 14 Apr 2022 10:28:23 GMT nox > python -m OpenSSL.debug
Thu, 14 Apr 2022 10:28:24 GMT pyOpenSSL: 22.0.0

Copy-friendly signature

signature.txt

Failure Signature
-----------------
Thu, 14 Apr 2022 10:28:23 GMT nox > python -m OpenSSL.debug
Thu, 14 Apr 2022 10:28:24 GMT pyOpenSSL: 22.0.0

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
Thu, 14 Apr 2022 10:28:23 GMT nox > python -m OpenSSL.debug
Thu, 14 Apr 2022 10:28:24 GMT pyOpenSSL: 22.0.0

Minimal Reproduction

repro.py

#!/bin/bash

set -exo pipefail

make clean
./configure
make
./python -m ensurepip
./python -m pip install ~/urllib3
./python -m pip install -r ~/urllib3/dev-requirements.txt
timeout 15 ./python -m pytest ~/urllib3/test/with_dummyserver/test_proxy_poolmanager.py::TestHTTPProxyManager

Environment

Python: 3.11.0

What Broke

CI tests hang indefinitely or run significantly slower, impacting deployment timelines.

Fix Options (Details)

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

pip install urllib3==1.26.10

When NOT to use: Do not use if it changes public behavior or if the failure cannot be reproduced.

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/2620

First fixed release: 1.26.10

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

When NOT to Use This Fix

Do not use if it changes public behavior or if the failure cannot be reproduced.

Verify Fix

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

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
1.1.1	Broken
1.26.10	Fixed

Related Issues

No related fixes found.

Cluster: urllib3:ssl-handshake urllib3 hub urllib3 best practices All hubs All clusters

Related clusters: Configuration error Data consistency Other

Sources

We don’t republish the full GitHub discussion text. Use the links above for context.