aiohttp `RequestInfo` change to a named tuple broke BC (Fix)

The Fix

Added a backward compatibility layer to `RequestInfo` to allow creating these objects without a `real_url`.

Based on closed aio-libs/aiohttp issue #9866 · 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%.

Jump to Verify Open PR/Commit

@@ -0,0 +1 @@
@@ -0,0 +1 @@
+Added a backward compatibility layer to `~aiohttp.RequestInfo` to allow creating these objects without a `real_url` -- by :user:`bdraco`.
diff --git a/aiohttp/client_reqrep.py b/aiohttp/client_reqrep.py
index 8e7ebbcbebe..8f7ed23f286 100644

repro.py

"""
Reproduce a regression in aiohttp 3.11.0.
"""

from multidict import CIMultiDict, CIMultiDictProxy

from aiohttp.client_reqrep import RequestInfo
from yarl import URL

RequestInfo(URL(), "GET", CIMultiDictProxy(CIMultiDict()))

verify

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

fix.md

Option A — Apply the official fix\nAdded a backward compatibility layer to `RequestInfo` to allow creating these objects without a `real_url`.\nWhen NOT to use: This fix should not be used if the application relies on the new behavior of requiring real_url.\n\n

Why This Fix Works in Production

Trigger: `RequestInfo` change to a named tuple broke BC
Mechanism: The change in RequestInfo to a named tuple made real_url a required argument, breaking existing code

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

The change in RequestInfo to a named tuple made real_url a required argument, breaking existing code
Production symptom (often without a traceback): `RequestInfo` change to a named tuple broke BC

Proof / Evidence

GitHub issue: #9866
Fix PR: https://github.com/aio-libs/aiohttp/pull/9873
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.80
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.62

Discussion

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

Jump to Sources Open on GitHub

“Please see https://github.com/pnuckowski/aioresponses/pull/262”

@bdraco · 2024-11-13 · source

“My initial call on this was we didn't want to change it because we don't expect these objects to be created externally but since there…”

@bdraco · 2024-11-14 · source

“This is expected. Its mentioned as breaking in the changelog <img width="677" alt="Screenshot 2024-11-13 at 1 46 17 PM" src="https://github.com/user-attachments/assets/f45ae766-6f85-4ca5-a110-b8e25076b59b">”

@bdraco · 2024-11-13 · source

“fyi this is breaking for https://github.com/pnuckowski/aioresponses”

@d1manson · 2024-11-13 · source

Failure Signature (Search String)

`RequestInfo` change to a named tuple broke BC
Existing usage of aiohttp 3.10 no longer works with aiohttp 3.13, causing the following error: `TypeError: RequestInfo.__new__() missing 1 required positional argument: 'real_url'`

Copy-friendly signature

signature.txt

Failure Signature
-----------------
`RequestInfo` change to a named tuple broke BC
Existing usage of aiohttp 3.10 no longer works with aiohttp 3.13, causing the following error: `TypeError: RequestInfo.__new__() missing 1 required positional argument: 'real_url'`

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
`RequestInfo` change to a named tuple broke BC
Existing usage of aiohttp 3.10 no longer works with aiohttp 3.13, causing the following error: `TypeError: RequestInfo.__new__() missing 1 required positional argument: 'real_url'`

Minimal Reproduction

repro.py

"""
Reproduce a regression in aiohttp 3.11.0.
"""

from multidict import CIMultiDict, CIMultiDictProxy

from aiohttp.client_reqrep import RequestInfo
from yarl import URL

RequestInfo(URL(), "GET", CIMultiDictProxy(CIMultiDict()))

What Broke

Users encountered TypeError when creating RequestInfo without real_url, causing application failures.

Why It Broke

The change in RequestInfo to a named tuple made real_url a required argument, breaking existing code

Fix Options (Details)

Option A — Apply the official fix

Added a backward compatibility layer to `RequestInfo` to allow creating these objects without a `real_url`.

When NOT to use: This fix should not be used if the application relies on the new behavior of requiring real_url.

Fix reference: https://github.com/aio-libs/aiohttp/pull/9873

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

When NOT to Use This Fix

This fix should not be used if the application relies on the new behavior of requiring real_url.

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

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.

Related Issues

No related fixes found.

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Related clusters: Data consistency Race condition Auth

Sources

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