[BUG] licence file included despite explicitly excluded via MANIFEST.in

setuptools version

68.0.0

Python version

3.11.4

OS

Debian sid

Additional environment information

Also using python3-setuptools-scm 7.1.0

Description

I have a project using pyproject.toml which includes a file LICENCE and a symlink COPYING to that.

It seems that setuptools cannot include symlinks (🙁) but instead resolves the, so the very same file is included twice, making the sdist and wheel needlessly bigger.

One way of solving this, would be supporting symlinks ;-) ... or perhaps not including the file if it's a symlink to an already included file (an perhaps restricting this to the recognised licences files?).

Anyway, my issue here is, that I've set up a MANIFEST.in with:

exclude COPYING

yet it still includes the file, which I think it shouldn't do, or should it?

Only if I set:

[tool.setuptools]
license-files = ['LICEN[CS]E*', 'NOTICE*', 'AUTHORS*']

in pyproject.toml it really excludes the file (or probably rather not even includes it in the first place, regardless of my MANIFEST.in.

Expected behavior

Files explicitly excluded, should be excluded. :-)

How to Reproduce

1. Create a simple empty project with LICENCE and COPYING as a symlink to it, as well a a default pyproject.toml
2. Also MANIFEST.in as described above
3. Create a sdist
4. It will have the COPYING despite the exclusion.

Output

not applicable

Reproduce the issue with a project containing LICENCE, a COPYING symlink, pyproject.toml, and MANIFEST.in containing exclude COPYING; then inspect the generated sdist. Compare this with the configuration using license-files in pyproject.toml. Done means an explicit MANIFEST.in exclusion prevents COPYING from appearing in the sdist.