setuptools version

setuptools==74.1.2

Python version

Python 3.13

OS

any

Additional environment information

No response

Description

If any of the the glob patterns specified intool.setuptools.license-files matches a file in the package, setuptools generates invalid metadata: it includes a License-File field while specifying Metadata-Version to be 2.1. This is invalid and packaging raises an exception while parsing the metadata. This likely results in the resulting distributions to not be accepted by PyPI.

Because tool.setuptools.license-files has a default value of ['LICEN[CS]E*', 'COPYING*', 'NOTICE*', 'AUTHORS*'] the problem can be encountered also in packages that do not explicitly set this field in pyproject.toml but happen to have a file matching the default glob pattern.

Expected behavior

Do not emit the License-File field or do it and specify Metadata-Version: 2.4 as per PEP 639.

How to Reproduce

Here is a short reproducer:

$ cat >pyproject.toml <<EOF
[build-system]
requires = ["setuptools"]
build-backend = "setuptools.build_meta"
[project]
name = "foo"
version = "1.2.3"
[tool.setuptools]
license-files = ["LICENSE"]
EOF
$ touch LICENSE
$ uv build .
$ tar xf dist/foo-1.2.3.tar.gz
$ python
>>> import pathlib
>>> import packaging.metadata
>>> packaging.metadata.Metadata.from_email(pathlib.Path('dist/foo-1.2.3/PKG-INFO').read_text())

Output

  + Exception Group Traceback (most recent call last):
  |   File "<python-input-3>", line 1, in <module>
  |     packaging.metadata.Metadata.from_email(pathlib.Path('dist/foo-1.2.3/PKG-INFO').read_text())
  |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |   File "/Users/daniele/src/twine/.venv/lib/python3.13/site-packages/packaging/metadata.py", line 781, in from_email
  |     raise ExceptionGroup(
  |         "invalid or unparsed metadata", exc_group.exceptions
  |     ) from None
  | ExceptionGroup: invalid or unparsed metadata (1 sub-exception)
  +-+---------------- 1 ----------------
    | packaging.metadata.InvalidMetadata: license-file introduced in metadata version 2.4, not 2.1
    +------------------------------------
>>>