From Fedora Project Wiki


Packaging 22+

Summary

Update to a new upstream release of python-packaging contains a breaking change. Since version 22+ upstream removed support for LegacySpecifier and LegacyVersion some packages will break. This is a breaking change and projects are encouraged to use versions adherent to PEP 440.

Owner


Current status

  • Targeted release: Fedora Linux 38
  • Last updated: 2023-01-24
  • FESCo issue: <will be assigned by the Wrangler>
  • Tracker bug: <will be assigned by the Wrangler>
  • Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

>>> # before 22.0
>>> packaging.version.parse("This is a completely random string")
<LegacyVersion('This is a completely random string')>
>>> # after 22.0
>>> packaging.version.parse("This is a completely random string")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "[...]/.venv/lib/python3.10/site-packages/packaging/version.py", line 52, in parse
    return Version(version)
  File "[...]/.venv/lib/python3.10/site-packages/packaging/version.py", line 197, in __init__
    raise InvalidVersion(f"Invalid version: '{version}'")
packaging.version.InvalidVersion: Invalid version: 'This is a completely random string'

This "feature" has been deprecated for nearly two years now.

PyPI has not permitted uploading packages with invalid versions for even more years. The latest versions of pip should be rejecting/erroring out on wheels with such versions as well. The stricter metadata validation helps pip's dependency resolver's logic, along with helping the broader ecology avoid needing to deal with outside-of-standard tooling/behaviours.

Feedback

Benefit to Fedora

Packaging 22+ contains a handwritten parser for parsing requirements and markers. Thanks to this, packaging has dropped a runtime dependency on pyparsing and from now on is not depending on any package on runtime. This will simplify bootstrapping of the next Python.

Scope

  • Proposal owners:
  • Other developers:
  • Policies and guidelines: N/A (not needed for this Change)
  • Trademark approval: N/A (not needed for this Change)
  • Alignment with Objectives:

Upgrade/compatibility impact

How To Test

User Experience

Dependencies

Contingency Plan

  • Contingency mechanism: (What to do? Who will do it?) N/A (not a System Wide Change)
  • Contingency deadline: N/A (not a System Wide Change)
  • Blocks release? N/A (not a System Wide Change), Yes/No


Documentation

N/A (not a System Wide Change)

Release Notes