Thank you very much@frenzymadness for having a look on this issue and proposing a solution.

I think we have 2 options according tohttps://setuptools.pypa.io/en/latest/development/developer-guide.html#code-conventions-and-other-practices (see description about modifying files in the_distutils folder):

1. Contribute this change to thepypa/distutils repository (requires changing the test cases to another file that exists in thepypa/distutils repository).
2. Attempt to implement a different change outside of the_distutils folder.

In the case we go for a change in thepypa/setuptools repository, I believe that the best here is to comply with the documented behaviour and raise an error when\n is used (maintainers ofpypa/distutils might have a different opinion).

You are right, sorry. Let me take this to distutils and see what they think about this change there.