urllib3 Tests randomly fail in pipeline due to timeout (Fix)

The Fix

pip install urllib3==1.26.13

Based on closed urllib3/urllib3 issue #2815 · PR/commit linked

Production note: This usually shows up under retries/timeouts. Treat it as a side-effect risk until you can verify behavior with a canary + real traffic.

Open PR/Commit

@@ -85,7 +85,7 @@ jobs:
     name: ${{ fromJson('{"macos-11":"macOS","windows-latest":"Windows","ubuntu-latest":"Ubuntu","ubuntu-20.04":"Ubuntu 20.04 (OpenSSL 1.1.1)","ubuntu-22.04":"Ubuntu 22.04 (OpenSSL 3.0)"}')[matrix.os] }} ${{ matrix.python-version }} ${{ matrix.nox-session}}
     continue-on-error: ${{ matrix.experimental }}
-    timeout-minutes: 20
+    timeout-minutes: 30
     steps:

fix.md

Option A — Upgrade to fixed release\npip install urllib3==1.26.13\nWhen NOT to use: This fix is not suitable if tests consistently exceed the new timeout limit.\n\n

Why This Fix Works in Production

Trigger: Tests randomly fail in pipeline due to timeout
Mechanism: The test timeout was set to 20 minutes, causing random test failures in the CI pipeline
Why the fix works: Increased the test timeout for GitHub Actions from 20 minutes to 30 minutes to prevent random test failures due to timeouts. (first fixed release: 1.26.13).

Production impact:

If left unfixed, retry loops can amplify load and turn a small outage into a cascade (thundering herd).

Why This Breaks in Prod

The test timeout was set to 20 minutes, causing random test failures in the CI pipeline
Production symptom (often without a traceback): Tests randomly fail in pipeline due to timeout

Proof / Evidence

GitHub issue: #2815
Fix PR: https://github.com/urllib3/urllib3/pull/2818
First fixed release: 1.26.13
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.68

Discussion

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

Jump to Sources Open on GitHub

“### Subject The heavy lifting of the tests is currently limited to a 20mins timeout. (https://github.com/urllib3/urllib3/blob/main/.github/workflows/ci.yml#L88) -- however, the actual execution time on the CI pipeline for the **same** tests”

Issue thread · issue description · source

Failure Signature (Search String)

Tests randomly fail in pipeline due to timeout
I propose to either increase the timeout to 30mins or finding the individual tests that take so long and fix them somehow.

Copy-friendly signature

signature.txt

Failure Signature
-----------------
Tests randomly fail in pipeline due to timeout
I propose to either increase the timeout to 30mins or finding the individual tests that take so long and fix them somehow.

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
Tests randomly fail in pipeline due to timeout
I propose to either increase the timeout to 30mins or finding the individual tests that take so long and fix them somehow.

What Broke

Tests fail intermittently in the CI pipeline due to timeout issues.

Why It Broke

The test timeout was set to 20 minutes, causing random test failures in the CI pipeline

Fix Options (Details)

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

pip install urllib3==1.26.13

When NOT to use: This fix is not suitable if tests consistently exceed the new timeout limit.

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/2818

First fixed release: 1.26.13

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

When NOT to Use This Fix

This fix is not suitable if tests consistently exceed the new timeout limit.

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.
Make timeouts explicit and test them (unit + integration) to avoid silent behavior changes.
Instrument retries (attempt count + reason) and alert on spikes to catch dependency slowdowns.

Version Compatibility Table

Version	Status
1.26.13	Fixed

Related Issues

No related fixes found.

Cluster: urllib3:retry-storm urllib3 hub urllib3 best practices All hubs All clusters

Related clusters: Configuration error Data consistency SSL handshake

Sources

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