When both maintainer and author contacts are passed to distutil's setup, the resulting PKG-INFO file has only an author field (set to the maintainer contact!).  The original author contact information is discarded.

Both maintainer and author contacts should be preserved.  If PKG-INFO doesn't support a maintainer contact, it should be added to the spec.

"""
from distutils.core import setup
setup(name="foo", author="bar", maintainer="baz")
"""
gives me
"""
Metadata-Version: 1.0
Name: foo
Version: 0.0.0
Summary: UNKNOWN
Home-page: UNKNOWN
Author: baz
Author-email: UNKNOWN
License: UNKNOWN
Description: UNKNOWN
Platform: UNKNOWN
"""

the Author metadata uses the maintainer field *or* the author field if
the maintainer is not provided.

What would be the rational to add a new maintainer field in the PKG-INFO ?

In the first place, I am wondering what is the rational, today, to use
the maintainer argument at all.

John, can you detail this ?

Tarek, should we change component to Distutils2?

From PEP 345: “Note that this field is intended for use when a project is being maintained by someone other than the original author: it should be omitted if it is identical to Author.”

It’s therefore logical that maintainer wins over author: The metadata file wants a contact point, so if the original author is not active anymore and there is another person acting as maintainer, the maintainer is the contact.

This is IMO a documentation bug, which I’m assigning to distutils2 (distutils docs only get quick fixes for things that don’t work at all).

I think this might be more than a documentation bug. Akira's example shows
that the maintainer is erroneously listed as the author. This does not
seem fair to an author who in general will have written most of a package.

I'd prefer a separate maintainer field.

PEP 345 adds a Maintainer field to fix this, and this is now present and active in Ditsutils2. You can now have both.