Build system updates needed soon

[llimeht]

As the sands steadily shift in python packaging, the following warnings are now emitted about upcoming changes:

/usr/lib/python3/dist-packages/setuptools/dist.py:599: SetuptoolsDeprecationWarning: Invalid dash-separated key 'license-file' in 'metadata' (setup.cfg), please use the underscore name 'license_file' instead.
!!

        ********************************************************************************
        Usage of dash-separated 'license-file' will not be supported in future
        versions. Please use the underscore name 'license_file' instead.

        By 2026-Mar-03, you need to update your project and remove deprecated calls
        or your builds will no longer be supported.

        See https://setuptools.pypa.io/en/latest/userguide/declarative_config.html for details.
        ********************************************************************************

!!

/usr/lib/python3/dist-packages/setuptools/dist.py:759: SetuptoolsDeprecationWarning: License classifiers are deprecated.
!!

        ********************************************************************************
        Please consider removing the following classifiers in favor of a SPDX license expression:

        License :: OSI Approved :: MIT License

        See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
        ********************************************************************************

!!

/usr/lib/python3/dist-packages/setuptools/_distutils/cmd.py:90: SetuptoolsDeprecationWarning: setup.py install is deprecated.
!!

        ********************************************************************************
        Please avoid running ``setup.py`` directly.
        Instead, use pypa/build, pypa/installer or other
        standards-based tools.

        See https://blog.ganssle.io/articles/2021/10/setup-py-deprecated.html for details.
        ********************************************************************************

!!

reading manifest template 'MANIFEST.in'
warning: no files found matching '*' under directory 'tests'
warning: no previously-included files matching '__pycache__' found under directory '*'
warning: no previously-included files matching '*.py[co]' found under directory '*'
warning: no files found matching '*.jpg' under directory 'docs'
warning: no files found matching '*.png' under directory 'docs'
warning: no files found matching '*.gif' under directory 'docs'

/usr/lib/python3/dist-packages/setuptools/command/build_py.py:212: _Warning: Package 'orsopy.fileio.schema' is absent from the `packages` configuration.
!!

        ********************************************************************************
        ############################
        # Package would be ignored #
        ############################
        Python recognizes 'orsopy.fileio.schema' as an importable package[^1],
        but it is absent from setuptools' `packages` configuration.

        This leads to an ambiguous overall configuration. If you want to distribute this
        package, please make sure that 'orsopy.fileio.schema' is explicitly added
        to the `packages` configuration field.

        Alternatively, you can also rely on setuptools' discovery methods
        (for example by using `find_namespace_packages(...)`/`find_namespace:`
        instead of `find_packages(...)`/`find:`).

        You can read more about "package discovery" on setuptools documentation page:

        - https://setuptools.pypa.io/en/latest/userguide/package_discovery.html

        If you don't want 'orsopy.fileio.schema' to be distributed and are
        already explicitly excluding 'orsopy.fileio.schema' via
        `find_namespace_packages(...)/find_namespace` or `find_packages(...)/find`,
        you can try to use `exclude_package_data`, or `include-package-data=False` in
        combination with a more fine grained `package-data` configuration.

        You can read more about "package data files" on setuptools documentation page:

        - https://setuptools.pypa.io/en/latest/userguide/datafiles.html


        [^1]: For Python, any directory (with suitable naming) can be imported,
              even if it does not contain any `.py` files.
              On the other hand, currently there is no concept of package data
              directory, all directories are treated like packages.
        ********************************************************************************

!!

/usr/lib/python3/dist-packages/setuptools/command/build_py.py:212: _Warning: Package 'orsopy.slddb.element_table.nabs_geant4' is absent from the `packages` configuration.
!!

        ********************************************************************************
        ############################
        # Package would be ignored #
        ############################
        Python recognizes 'orsopy.slddb.element_table.nabs_geant4' as an importable package[^1],
        but it is absent from setuptools' `packages` configuration.

        This leads to an ambiguous overall configuration. If you want to distribute this
        package, please make sure that 'orsopy.slddb.element_table.nabs_geant4' is explicitly added
        to the `packages` configuration field.

        Alternatively, you can also rely on setuptools' discovery methods
        (for example by using `find_namespace_packages(...)`/`find_namespace:`
        instead of `find_packages(...)`/`find:`).

        You can read more about "package discovery" on setuptools documentation page:

        - https://setuptools.pypa.io/en/latest/userguide/package_discovery.html

        If you don't want 'orsopy.slddb.element_table.nabs_geant4' to be distributed and are
        already explicitly excluding 'orsopy.slddb.element_table.nabs_geant4' via
        `find_namespace_packages(...)/find_namespace` or `find_packages(...)/find`,
        you can try to use `exclude_package_data`, or `include-package-data=False` in
        combination with a more fine grained `package-data` configuration.

        You can read more about "package data files" on setuptools documentation page:

        - https://setuptools.pypa.io/en/latest/userguide/datafiles.html


        [^1]: For Python, any directory (with suitable naming) can be imported,
              even if it does not contain any `.py` files.
              On the other hand, currently there is no concept of package data
              directory, all directories are treated like packages.
        ********************************************************************************

!!

[andyfaff]

If I use python -m build . then I can see orsopy.slddb.element_table.nabs_geant4 and orsopy.fileio.schema being included. THey're present in setup.cfg --> options.package_data. How do we fix those warnings?

[llimeht]

If I use python -m build . then I can see orsopy.slddb.element_table.nabs_geant4 and orsopy.fileio.schema being included. THey're present in setup.cfg --> options.package_data. How do we fix those warnings?

There's nothing pleasant about data files and setuptools... There are also substantial differences in the defaults depending on whether it is configured via setup.cfg or pyproject.toml; moving to pyproject.toml so that standard build tools will invoke via build rather than setup.py is a worthwhile first step before sinking time into the data files.

As the link about data files in the warning says, Python has no concept of a data directory and all directories are importable. A quick and dirty way of doing it is to create orsopy/fileio/schema/__init__.py which means that it is then discovered by find and so is definitely wanted and no longer ambiguous (noting that namespace package handling differs between setup.cfg and pyproject.toml). One can probably likewise exclude it from find (and include it only via package_data) and then it is not ambiguous.

[andyfaff]

I think all those warnings were addressed.