package data in subdirectory causes warning

setuptools version

62.3.2

Python version

3.10

OS

Debian with conda

Additional environment information

No response

Description

pyopencl has OpenCL files and some headers in a subdirectory pyopencl/cl and they are included as package_data so that the python module can find them.

package_data={
                    "pyopencl": [
                        "cl/*.cl",
                        "cl/*.h",
                        "cl/pyopencl-random123/*.cl",
                        "cl/pyopencl-random123/*.h",
                        ]
                    },

With new setuptools, there is a warning saying

    ############################
    # Package would be ignored #
    ############################
    Python recognizes 'pyopencl.cl' as an importable package, however it is
    included in the distribution as "data".
    This behavior is likely to change in future versions of setuptools (and
    therefore is considered deprecated).

    Please make sure that 'pyopencl.cl' is included as a package by using
    setuptools' `packages` configuration field or the proper discovery methods
    (for example by using `find_namespace_packages(...)`/`find_namespace:`
    instead of `find_packages(...)`/`find:`).

    You can read more about "package discovery" and "data files" on setuptools
    documentation page.

cc @inducer

Expected behavior

No warning

How to Reproduce

1. clone https://github.com/inducer/pyopencl
2. install numpy
3. Run python setup.py install

Output

$ python setup.py install
running install
/home/idf2/miniforge3/lib/python3.10/site-packages/setuptools/command/install.py:34: SetuptoolsDeprecationWarning: setup.py install is deprecated. Use build and pip and other standards-based tools.
  warnings.warn(
/home/idf2/miniforge3/lib/python3.10/site-packages/setuptools/command/easy_install.py:144: EasyInstallDeprecationWarning: easy_install command is deprecated. Use build and pip and other standards-based tools.
  warnings.warn(
running bdist_egg
running egg_info
writing pyopencl.egg-info/PKG-INFO
writing dependency_links to pyopencl.egg-info/dependency_links.txt
writing requirements to pyopencl.egg-info/requires.txt
writing top-level names to pyopencl.egg-info/top_level.txt
reading manifest file 'pyopencl.egg-info/SOURCES.txt'
reading manifest template 'MANIFEST.in'
adding license file 'LICENSE'
writing manifest file 'pyopencl.egg-info/SOURCES.txt'
installing library code to build/bdist.linux-x86_64/egg
running install_lib
running build_py
/home/idf2/miniforge3/lib/python3.10/site-packages/setuptools/command/build_py.py:153: SetuptoolsDeprecationWarning:     Installing 'pyopencl.cl' as data is deprecated, please list it in `packages`.
    !!


    ############################
    # Package would be ignored #
    ############################
    Python recognizes 'pyopencl.cl' as an importable package, however it is
    included in the distribution as "data".
    This behavior is likely to change in future versions of setuptools (and
    therefore is considered deprecated).

    Please make sure that 'pyopencl.cl' is included as a package by using
    setuptools' `packages` configuration field or the proper discovery methods
    (for example by using `find_namespace_packages(...)`/`find_namespace:`
    instead of `find_packages(...)`/`find:`).

    You can read more about "package discovery" and "data files" on setuptools
    documentation page.


!!

  check.warn(importable)
running build_ext

Start by reproducing the warning from the pyopencl setup.py package_data configuration with Python 3.10 and setuptools 62.3.2. Read the package discovery and build_py warning paths in setuptools, then verify the behavior against the reported OpenCL and header files. Done means the reported installation no longer emits this warning without breaking inclusion of the package data.