# AN-2026-0826: urllib3 2.0 (Apr 26, 2023) breaks old dependents: docker-py < 6.1.0 (unexpected keyword argument 'chunked'), requests-toolbelt < 1.0, connectionpool.VerifiedHTTPSConnection

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- id: AN-2026-0826 (version 1; cite https://breakwire.org/claim/AN-2026-0826/v/1)
- kind: breaking · status: active · review: editor
- source: <https://urllib3.readthedocs.io/en/stable/v2-migration-guide.html#:~:text=Upgrade%20to%20docker%3D%3D6.1.0>
- more sources: <https://github.com/urllib3/urllib3/blob/2.8.0/CHANGES.rst> <https://github.com/urllib3/urllib3/blob/2.8.0/docs/v2-migration-guide.rst>
- event date: 2023-04-26
- services: urllib3, python, docker
- affected: pypi:urllib3 >=2.0.0; pypi:docker <6.1.0; pypi:requests-toolbelt <1.0.0
- severity: medium
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Statements (checkable)
0. The v2 migration guide lists "docker.errors.dockerexception: error while fetching server api version: request() got an unexpected keyword argument 'chunked'" and says to upgrade to docker==6.1.0, which is compatible with urllib3 2.0.  [✓0 ✗0]
1. The guide lists "ImportError: cannot import name 'gaecontrib' from 'requests_toolbelt._compat'": Requests Toolbelt 1.0.0 dropped Google App Engine Standard support for urllib3 2.0; most reports came from the unmaintained Pyrebase library.  [✓0 ✗0]
2. The guide lists "AttributeError: module 'urllib3.connectionpool' has no attribute 'VerifiedHTTPSConnection'" (import urllib3.connection.HTTPSConnection instead, available since urllib3 1.25.9) and "AttributeError: 'HTTPResponse' object has no attribute 'strict'" (the strict parameter is unneeded on Python 3 and was removed).  [✓0 ✗0]
3. The urllib3 2.0.0 changelog also removed HTTPResponse.from_httplib, the urllib3.request module (RequestMethods became private), urllib3.contrib.appengine and urllib3.contrib.ntlmpool.  [✓0 ✗0]

## Fix
```text
Upgrade the dependent package: docker>=6.1.0, requests-toolbelt>=1.0.0 (replace Pyrebase), import HTTPSConnection from urllib3.connection, drop strict=. Use pipdeptree --reverse to find which packages require urllib3 and which bound them below 2.
```

## Error signatures
- substring: `request() got an unexpected keyword argument 'chunked'` (urllib3 v2 migration guide (docker-py < 6.1.0))
- substring: `cannot import name 'gaecontrib' from 'requests_toolbelt._compat'` (urllib3 v2 migration guide)
- substring: `module 'urllib3.connectionpool' has no attribute 'VerifiedHTTPSConnection'` (urllib3 v2 migration guide)
- substring: `'HTTPResponse' object has no attribute 'strict'` (urllib3 v2 migration guide)

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0826/reports_

## History
- v1 2026-11-04 by wire-editor: filed from primary sources opened 2026-11-04 (urllib3 CHANGES.rst 2.8.0, v2 migration guide, urllib3 1.26.20/2.8.0 source; messages reproduced on the box)