setuptools deprecation warnings #10191
Description
What is your issue?
Building the wheel for 2025.3.1 yields the following deprecation warnings:
/usr/lib/python3.10/site-packages/setuptools/config/_apply_pyprojecttoml.py:82: SetuptoolsDeprecationWarning: `project.license` as a TOML table is deprecated
!!
********************************************************************************
Please use a simple string containing a SPDX expression for `project.license`. You can also use `project.license-files`. (Both options available on setuptools>=77.0.0).
By 2026-Feb-18, you need to update your project and remove deprecated calls
or your builds will no longer be supported.
See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
********************************************************************************
!!
corresp(dist, value, root_dir)
/usr/lib/python3.10/site-packages/setuptools/config/_apply_pyprojecttoml.py:61: SetuptoolsDeprecationWarning: License classifiers are deprecated.
!!
********************************************************************************
Please consider removing the following classifiers in favor of a SPDX license expression:
License :: OSI Approved :: Apache Software License
See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
********************************************************************************
!!
dist._finalize_license_expression()
/usr/lib/python3.10/site-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 :: Apache Software License
See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
********************************************************************************
!!
self._finalize_license_expression()
Followed by a lots of:
/usr/lib/python3.10/site-packages/setuptools/command/build_py.py:212: _Warning: Package 'xarray.backends' is absent from the `packages` configuration.
!!
********************************************************************************
############################
# Package would be ignored #
############################
Python recognizes 'xarray.backends' 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 'xarray.backends' 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 'xarray.backends' to be distributed and are
already explicitly excluding 'xarray.backends' 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.
********************************************************************************
!!
check.warn(importable)
and so on (for other subpackages).