Bump pip from 26.0.1 to 26.1

[dependabot]

Bumps pip from 26.0.1 to 26.1.

Changelog

Sourced from pip's changelog.

26.1 (2026-04-26)

Deprecations and Removals

• Drop support for Python 3.9. ([#13795](https://github.com/pypa/pip/issues/13795) <https://github.com/pypa/pip/issues/13795>_)

Features

• Add experimental support to read requirements from standardized pylock.toml files (-r pylock.toml). ([#13876](https://github.com/pypa/pip/issues/13876) <https://github.com/pypa/pip/issues/13876>_)
• Allow --uploaded-prior-to to accept a duration in days (e.g., P3D for 3 days ago). ([#13674](https://github.com/pypa/pip/issues/13674) <https://github.com/pypa/pip/issues/13674>_)

Enhancements

• Speed up dependency resolution when there are complex conflicts. ([#13859](https://github.com/pypa/pip/issues/13859) <https://github.com/pypa/pip/issues/13859>_)
• Reduce memory usage when resolving large dependency trees. ([#13843](https://github.com/pypa/pip/issues/13843) <https://github.com/pypa/pip/issues/13843>_)
• Emit a deprecation warning when pip imports an unexpected module after installation of a distribution has started. ([#13912](https://github.com/pypa/pip/issues/13912) <https://github.com/pypa/pip/issues/13912>_)
• Allow URL constraints to apply to requirements with extras. ([#12018](https://github.com/pypa/pip/issues/12018) <https://github.com/pypa/pip/issues/12018>_)
• Allow unpinned requirements to use hashes from constraints. Constraints like {name}=={version} --hash=... feeds into hash verification for a corresponding requirement. ([#9243](https://github.com/pypa/pip/issues/9243) <https://github.com/pypa/pip/issues/9243>_)
• Improve conflict reports that involve direct URLs. ([#13932](https://github.com/pypa/pip/issues/13932) <https://github.com/pypa/pip/issues/13932>_)
• Show all errors instead of first error for faulty dependency_groups definitions. ([#13917](https://github.com/pypa/pip/issues/13917) <https://github.com/pypa/pip/issues/13917>_)

Bug Fixes

• Fix recovery hint for missing RECORD file to use --ignore-installed instead of --force-reinstall. ([#12645](https://github.com/pypa/pip/issues/12645) <https://github.com/pypa/pip/issues/12645>_)
• Fix misleading error message when a constraint file cannot be opened. ([#13226](https://github.com/pypa/pip/issues/13226) <https://github.com/pypa/pip/issues/13226>_)
• Show the filename rather than the full URL when downloading files from non-PyPI indexes in non-verbose mode. ([#13494](https://github.com/pypa/pip/issues/13494) <https://github.com/pypa/pip/issues/13494>_)
• Remove the adjacent __pycache__ directory when a .py file is removed. ([#13725](https://github.com/pypa/pip/issues/13725) <https://github.com/pypa/pip/issues/13725>_)
• Force UTF-8 encoding for :pep:723 metadata. ([#13861](https://github.com/pypa/pip/issues/13861) <https://github.com/pypa/pip/issues/13861>_)
• Minor performance improvement when filtering candidates during resolution. ([#13916](https://github.com/pypa/pip/issues/13916) <https://github.com/pypa/pip/issues/13916>_)
• Fix a hang on Windows when stdout is closed during verbose output. ([#13927](https://github.com/pypa/pip/issues/13927) <https://github.com/pypa/pip/issues/13927>_)
• Common path prefixes are determined by path segment, not character by character. ([#13847](https://github.com/pypa/pip/issues/13847) <https://github.com/pypa/pip/issues/13847>_)
• Fix installing .tar.gz source distributions that look like a zip file. ([#13867](https://github.com/pypa/pip/issues/13867) <https://github.com/pypa/pip/issues/13867>_)

Vendored Libraries

• Upgrade certifi to 2026.2.25
• Upgrade packaging to 26.2
• Upgrade requests to 2.33.1
• Upgrade tomli to 2.3.1
• Upgrade urllib3 to 2.6.3

... (truncated)

Commits

• 90b2b3e Bump for release
• 193f289 Update AUTHORS.txt
• 63c3709 Merge pull request #13876 from sbidoul/install-from-pylock-reqs-sbi
• e5fe702 Merge pull request #13949 from pypa/revert-13888-resolver-editable-links
• 122a14a Revert "Allow editable installs to satisfy direct-URL dependencies (#13888)"
• c335252 -r pylock.toml: add pip-wheel -r pylock.toml test
• ba2fc12 -r pylock.toml: proper error with remote pylock.toml containing directory ent...
• 747c4ae Merge pull request #13948 from ichard26/reword-news
• 3517841 -r pylock: refine filename pylock-ness test
• 2f7ad8c -r pylock.toml: fix crash with pip wheel and pip lock
• Additional commits viewable in compare view

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.92%. Comparing base (1842c3e) to head (12d6b2e).
⚠️ Report is 3 commits behind head on master.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #12427   +/-   ##
=======================================
  Coverage   98.92%   98.92%           
=======================================
  Files         134      134           
  Lines       46751    46751           
  Branches     2430     2430           
=======================================
  Hits        46249    46249           
  Misses        373      373           
  Partials      129      129           

Flag	Coverage Δ
CI-GHA	98.98% <ø> (ø)
OS-Linux	98.72% <ø> (-0.01%)	⬇️
OS-Windows	96.98% <ø> (ø)
OS-macOS	97.89% <ø> (+<0.01%)	⬆️
Py-3.10.11	97.39% <ø> (-0.01%)	⬇️
Py-3.10.20	97.86% <ø> (ø)
Py-3.11.15	98.12% <ø> (ø)
Py-3.11.9	97.64% <ø> (-0.01%)	⬇️
Py-3.12.10	97.73% <ø> (ø)
Py-3.12.13	98.20% <ø> (-0.01%)	⬇️
Py-3.13.13	98.45% <ø> (-0.01%)	⬇️
Py-3.14.4	98.51% <ø> (+<0.01%)	⬆️
Py-3.14.4t	97.51% <ø> (-0.01%)	⬇️
Py-pypy3.11.15-7.3.21	97.35% <ø> (+<0.01%)	⬆️
VM-macos	97.89% <ø> (+<0.01%)	⬆️
VM-ubuntu	98.72% <ø> (-0.01%)	⬇️
VM-windows	96.98% <ø> (ø)
cython-coverage	38.08% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
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[codspeed-hq]

Merging this PR will not alter performance

✅ 67 untouched benchmarks
⏩ 4 skipped benchmarks¹

---

_{Comparing dependabot/pip/pip-26.1 (12d6b2e) with master (1842c3e)²}

Footnotes

1. 4 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on master (c17e33f) during the generation of this report, so 1842c3e was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩