Requests __build__ out of sync? Still at 0x020503, looks

The Fix

pip install requests==2.27.0

Based on closed psf/requests issue #2530 · 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%.

Open PR/Commit

@@ -43,7 +43,7 @@
 __title__ = 'requests'
 __version__ = '2.6.0'
-__build__ = 0x020503
+__build__ = 0x020600
 __author__ = 'Kenneth Reitz'

fix.md

Option A — Upgrade to fixed release\npip install requests==2.27.0\nWhen NOT to use: Do not apply this fix if the build version number is already correct.\n\n

Why This Fix Works in Production

Trigger: __build__ out of sync? Still at 0x020503, looks like 2.5.3 rather than 2.6.0
Mechanism: __build__ version number was incorrectly set to 0x020503 instead of 0x020600
Why the fix works: Fixes the build version number in the metadata to reflect the correct version. (first fixed release: 2.27.0).

Production impact:

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

__build__ version number was incorrectly set to 0x020503 instead of 0x020600
Production symptom (often without a traceback): __build__ out of sync? Still at 0x020503, looks like 2.5.3 rather than 2.6.0

Proof / Evidence

GitHub issue: #2530
Fix PR: https://github.com/psf/requests/pull/2535
First fixed release: 2.27.0
Reproduced locally: No (not executed)
Last verified: 2026-02-07
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.79

Discussion

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

Jump to Sources Open on GitHub

“Could it be that at https://github.com/kennethreitz/requests/blob/master/requests/__init__.py#L46 went out of sync? It looks like 2.5.3 rather than 2.6.0. Best, Sebastian”

Issue thread · issue description · source

Failure Signature (Search String)

__build__ out of sync? Still at 0x020503, looks like 2.5.3 rather than 2.6.0
__build__ = 0x020503

Copy-friendly signature

signature.txt

Failure Signature
-----------------
__build__ out of sync? Still at 0x020503, looks like 2.5.3 rather than 2.6.0
__build__ = 0x020503

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
__build__ out of sync? Still at 0x020503, looks like 2.5.3 rather than 2.6.0
__build__ = 0x020503

What Broke

Users may experience confusion regarding the actual version of the library in use.

Why It Broke

__build__ version number was incorrectly set to 0x020503 instead of 0x020600

Fix Options (Details)

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

pip install requests==2.27.0

When NOT to use: Do not apply this fix if the build version number is already correct.

Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.

Fix reference: https://github.com/psf/requests/pull/2535

First fixed release: 2.27.0

Last verified: 2026-02-07. Validate in your environment.

When NOT to Use This Fix

Do not apply this fix if the build version number is already correct.

Did This Fix Work in Your Case?

Quick signal helps us prioritize which fixes to verify and improve.

Prevention

Capture the exact failing error string in logs and tests so you can reproduce via a minimal script.
Pin production dependencies and upgrade only with a reproducible test that hits the failing path.

Version Compatibility Table

Version	Status
2.27.0	Fixed

Related Issues

No related fixes found.

Cluster: requests:configuration-error Requests hub Requests best practices All hubs All clusters

Related clusters: Data consistency SSL handshake Other

Sources

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

Requests __build__ out of sync? Still at 0x020503, looks like 2.5.3 rather than 2.6.0 (Fix)