What is meant by "warning: no previously-included files found matching..."?

[Bernmeister]

Given the project using src-layout:

myproject
    pyproject.toml
    MANIFEST.in
    src
        mypkg
            a.py
            exclude_file.py

where MANIFEST.in contains:

exclude src/mypkg/exclude_file.py

and pyproject.toml contains the fragment:

[build-system]
requires = ["setuptools"]
build-backend = "setuptools.build_meta"

[tool.setuptools.packages.find]
where = [ "src" ]

When I run python3 -m build I get the expected and correct result of .tar.gz and .whl each containing a.py but not exclude_file.py. However, in the build output I see:

warning: no previously-included files found matching 'src/mypkg/exclude_file.py'

Could somebody shed some light on this for me please? Is there something which I need to correct as the warning seems to contradict the correct result. I wondered if not having __init__.py would make a difference but does not.

[abravalheri]

If I am not mistaken, you don't need to worry about that one (it is a logging.warnging, not a warnings.warn).

Possibly happens because when you run python -m build the wheel is built from the sdist, which already does not contain the file? (MANIFEST.in predates wheel).

I suppose you can turn the warnings filter up if you want to check which warnings are actionable by exporting PYTHONWARNINGS=error?

[Bernmeister]

@abravalheri Thanks for your answer.

Enabling PYTHONWARNINGS=error revealed no new information (related to the warnings).

I did notice the above mentioned warnings appear after the sdist is created and during the Getting build dependencies for wheel... and Building wheel... sections as you surmised.

Safely ignoring the warnings!