Deprecated licence classifier in setup.py

[loechel]

If Running release-check the following output / warning is raised:

release-check: commands[2]> python -m build --sdist --no-isolation
* Getting build dependencies for sdist...
/Users/ri62gep/workspaces/Plone/RestrictedPython/.tox/release-check/lib/python3.14/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 :: Zope Public License

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

!!
  self._finalize_license_expression()
running egg_info
writing src/RestrictedPython.egg-info/PKG-INFO
writing dependency_links to src/RestrictedPython.egg-info/dependency_links.txt
writing requirements to src/RestrictedPython.egg-info/requires.txt
writing top-level names to src/RestrictedPython.egg-info/top_level.txt
reading manifest file 'src/RestrictedPython.egg-info/SOURCES.txt'
reading manifest template 'MANIFEST.in'
adding license file 'LICENSE.txt'
writing manifest file 'src/RestrictedPython.egg-info/SOURCES.txt'
* Building sdist...
/Users/ri62gep/workspaces/Plone/RestrictedPython/.tox/release-check/lib/python3.14/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 :: Zope Public License

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

!!
  self._finalize_license_expression()
running sdist
running egg_info
writing src/RestrictedPython.egg-info/PKG-INFO
writing dependency_links to src/RestrictedPython.egg-info/dependency_links.txt
writing requirements to src/RestrictedPython.egg-info/requires.txt
writing top-level names to src/RestrictedPython.egg-info/top_level.txt
reading manifest file 'src/RestrictedPython.egg-info/SOURCES.txt'
reading manifest template 'MANIFEST.in'
adding license file 'LICENSE.txt'
writing manifest file 'src/RestrictedPython.egg-info/SOURCES.txt'
running check
creating restrictedpython-8.1.dev0
creating restrictedpython-8.1.dev0/docs
creating restrictedpython-8.1.dev0/docs/_build/doctest
creating restrictedpython-8.1.dev0/docs/_build/html/_images
creating restrictedpython-8.1.dev0/docs/_build/html/_sources
creating restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
creating restrictedpython-8.1.dev0/docs/_build/html/_sources/install
creating restrictedpython-8.1.dev0/docs/_build/html/_sources/roadmap
creating restrictedpython-8.1.dev0/docs/_build/html/_sources/upgrade_dependencies
creating restrictedpython-8.1.dev0/docs/_build/html/_sources/usage
creating restrictedpython-8.1.dev0/docs/_build/html/_static/scripts
creating restrictedpython-8.1.dev0/docs/contributing
creating restrictedpython-8.1.dev0/docs/contributing/ast
creating restrictedpython-8.1.dev0/docs/install
creating restrictedpython-8.1.dev0/docs/roadmap
creating restrictedpython-8.1.dev0/docs/usage
creating restrictedpython-8.1.dev0/src/RestrictedPython
creating restrictedpython-8.1.dev0/src/RestrictedPython.egg-info
creating restrictedpython-8.1.dev0/tests
creating restrictedpython-8.1.dev0/tests/builtins
creating restrictedpython-8.1.dev0/tests/transformer
creating restrictedpython-8.1.dev0/tests/transformer/operators
copying files to restrictedpython-8.1.dev0...
copying .pre-commit-config.yaml -> restrictedpython-8.1.dev0
copying .readthedocs.yaml -> restrictedpython-8.1.dev0
copying CHANGES.rst -> restrictedpython-8.1.dev0
copying CONTRIBUTING.md -> restrictedpython-8.1.dev0
copying COPYRIGHT.txt -> restrictedpython-8.1.dev0
copying LICENSE.txt -> restrictedpython-8.1.dev0
copying MANIFEST.in -> restrictedpython-8.1.dev0
copying README.rst -> restrictedpython-8.1.dev0
copying buildout.cfg -> restrictedpython-8.1.dev0
copying constraints.txt -> restrictedpython-8.1.dev0
copying pyproject.toml -> restrictedpython-8.1.dev0
copying setup.cfg -> restrictedpython-8.1.dev0
copying setup.py -> restrictedpython-8.1.dev0
copying tox.ini -> restrictedpython-8.1.dev0
copying docs/Makefile -> restrictedpython-8.1.dev0/docs
copying docs/changes.rst -> restrictedpython-8.1.dev0/docs
copying docs/conf.py -> restrictedpython-8.1.dev0/docs
copying docs/idea.rst -> restrictedpython-8.1.dev0/docs
copying docs/index.rst -> restrictedpython-8.1.dev0/docs
copying docs/logo.jpg -> restrictedpython-8.1.dev0/docs
copying docs/make.bat -> restrictedpython-8.1.dev0/docs
copying docs/requirements.txt -> restrictedpython-8.1.dev0/docs
copying docs/_build/doctest/output.txt -> restrictedpython-8.1.dev0/docs/_build/doctest
copying docs/_build/html/_images/logo.jpg -> restrictedpython-8.1.dev0/docs/_build/html/_images
copying docs/_build/html/_sources/changes.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources
copying docs/_build/html/_sources/idea.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources
copying docs/_build/html/_sources/index.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources
copying docs/_build/html/_sources/contributing/changes_from26to27.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from30to31.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from310to311.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from311to312.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from312to313.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from313to314.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from31to32.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from32to33.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from33to34.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from34to35.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from35to36.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from36to37.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from37to38.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from38to39.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/changes_from39to310.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/contributing/index.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/contributing
copying docs/_build/html/_sources/install/index.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/install
copying docs/_build/html/_sources/roadmap/index.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/roadmap
copying docs/_build/html/_sources/upgrade_dependencies/index.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/upgrade_dependencies
copying docs/_build/html/_sources/usage/api.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/usage
copying docs/_build/html/_sources/usage/basic_usage.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/usage
copying docs/_build/html/_sources/usage/framework_usage.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/usage
copying docs/_build/html/_sources/usage/index.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/usage
copying docs/_build/html/_sources/usage/policy.rst.txt -> restrictedpython-8.1.dev0/docs/_build/html/_sources/usage
copying docs/_build/html/_static/scripts/furo.js.LICENSE.txt -> restrictedpython-8.1.dev0/docs/_build/html/_static/scripts
copying docs/contributing/changes_from310to311.rst -> restrictedpython-8.1.dev0/docs/contributing
copying docs/contributing/changes_from311to312.rst -> restrictedpython-8.1.dev0/docs/contributing
copying docs/contributing/changes_from312to313.rst -> restrictedpython-8.1.dev0/docs/contributing
copying docs/contributing/changes_from313to314.rst -> restrictedpython-8.1.dev0/docs/contributing
copying docs/contributing/changes_from38to39.rst -> restrictedpython-8.1.dev0/docs/contributing
copying docs/contributing/changes_from39to310.rst -> restrictedpython-8.1.dev0/docs/contributing
copying docs/contributing/index.rst -> restrictedpython-8.1.dev0/docs/contributing
copying docs/contributing/ast/python3_10.ast -> restrictedpython-8.1.dev0/docs/contributing/ast
copying docs/contributing/ast/python3_11.ast -> restrictedpython-8.1.dev0/docs/contributing/ast
copying docs/contributing/ast/python3_12.ast -> restrictedpython-8.1.dev0/docs/contributing/ast
copying docs/contributing/ast/python3_13.ast -> restrictedpython-8.1.dev0/docs/contributing/ast
copying docs/contributing/ast/python3_14.ast -> restrictedpython-8.1.dev0/docs/contributing/ast
copying docs/contributing/ast/python3_8.ast -> restrictedpython-8.1.dev0/docs/contributing/ast
copying docs/contributing/ast/python3_9.ast -> restrictedpython-8.1.dev0/docs/contributing/ast
copying docs/install/index.rst -> restrictedpython-8.1.dev0/docs/install
copying docs/roadmap/index.rst -> restrictedpython-8.1.dev0/docs/roadmap
copying docs/usage/api.rst -> restrictedpython-8.1.dev0/docs/usage
copying docs/usage/basic_usage.rst -> restrictedpython-8.1.dev0/docs/usage
copying docs/usage/framework_usage.rst -> restrictedpython-8.1.dev0/docs/usage
copying docs/usage/index.rst -> restrictedpython-8.1.dev0/docs/usage
copying docs/usage/policy.rst -> restrictedpython-8.1.dev0/docs/usage
copying src/RestrictedPython/Eval.py -> restrictedpython-8.1.dev0/src/RestrictedPython
copying src/RestrictedPython/Guards.py -> restrictedpython-8.1.dev0/src/RestrictedPython
copying src/RestrictedPython/Limits.py -> restrictedpython-8.1.dev0/src/RestrictedPython
copying src/RestrictedPython/PrintCollector.py -> restrictedpython-8.1.dev0/src/RestrictedPython
copying src/RestrictedPython/Utilities.py -> restrictedpython-8.1.dev0/src/RestrictedPython
copying src/RestrictedPython/__init__.py -> restrictedpython-8.1.dev0/src/RestrictedPython
copying src/RestrictedPython/_compat.py -> restrictedpython-8.1.dev0/src/RestrictedPython
copying src/RestrictedPython/compile.py -> restrictedpython-8.1.dev0/src/RestrictedPython
copying src/RestrictedPython/transformer.py -> restrictedpython-8.1.dev0/src/RestrictedPython
copying src/RestrictedPython.egg-info/PKG-INFO -> restrictedpython-8.1.dev0/src/RestrictedPython.egg-info
copying src/RestrictedPython.egg-info/SOURCES.txt -> restrictedpython-8.1.dev0/src/RestrictedPython.egg-info
copying src/RestrictedPython.egg-info/dependency_links.txt -> restrictedpython-8.1.dev0/src/RestrictedPython.egg-info
copying src/RestrictedPython.egg-info/not-zip-safe -> restrictedpython-8.1.dev0/src/RestrictedPython.egg-info
copying src/RestrictedPython.egg-info/requires.txt -> restrictedpython-8.1.dev0/src/RestrictedPython.egg-info
copying src/RestrictedPython.egg-info/top_level.txt -> restrictedpython-8.1.dev0/src/RestrictedPython.egg-info
copying tests/__init__.py -> restrictedpython-8.1.dev0/tests
copying tests/helper.py -> restrictedpython-8.1.dev0/tests
copying tests/test_Guards.py -> restrictedpython-8.1.dev0/tests
copying tests/test_NamedExpr.py -> restrictedpython-8.1.dev0/tests
copying tests/test_Utilities.py -> restrictedpython-8.1.dev0/tests
copying tests/test_compile.py -> restrictedpython-8.1.dev0/tests
copying tests/test_compile_restricted_function.py -> restrictedpython-8.1.dev0/tests
copying tests/test_eval.py -> restrictedpython-8.1.dev0/tests
copying tests/test_imports.py -> restrictedpython-8.1.dev0/tests
copying tests/test_iterating_over_dict_items.py -> restrictedpython-8.1.dev0/tests
copying tests/test_print_function.py -> restrictedpython-8.1.dev0/tests
copying tests/builtins/test_limits.py -> restrictedpython-8.1.dev0/tests/builtins
copying tests/builtins/test_utilities.py -> restrictedpython-8.1.dev0/tests/builtins
copying tests/transformer/test_assert.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_assign.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_async.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_attribute.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_augassign.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_base_types.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_breakpoint.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_call.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_classdef.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_comparators.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_conditional.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_dict_comprehension.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_eval_exec.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_fstring.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_functiondef.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_generic.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_global_local.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_import.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_inspect.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_iterator.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_lambda.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_loop.py -> restrictedpython-8.1.dev0/tests/transformer
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copying tests/transformer/test_with_stmt.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/test_yield.py -> restrictedpython-8.1.dev0/tests/transformer
copying tests/transformer/operators/test_arithmetic_operators.py -> restrictedpython-8.1.dev0/tests/transformer/operators
copying tests/transformer/operators/test_bit_wise_operators.py -> restrictedpython-8.1.dev0/tests/transformer/operators
copying tests/transformer/operators/test_bool_operators.py -> restrictedpython-8.1.dev0/tests/transformer/operators
copying tests/transformer/operators/test_comparison_operators.py -> restrictedpython-8.1.dev0/tests/transformer/operators
copying tests/transformer/operators/test_identity_operators.py -> restrictedpython-8.1.dev0/tests/transformer/operators
copying tests/transformer/operators/test_logical_operators.py -> restrictedpython-8.1.dev0/tests/transformer/operators
copying tests/transformer/operators/test_unary_operators.py -> restrictedpython-8.1.dev0/tests/transformer/operators
copying src/RestrictedPython.egg-info/SOURCES.txt -> restrictedpython-8.1.dev0/src/RestrictedPython.egg-info
Writing restrictedpython-8.1.dev0/setup.cfg
Creating tar archive
removing 'restrictedpython-8.1.dev0' (and everything under it)
Successfully built restrictedpython-8.1.dev0.tar.gz

So we should remove that infavour of the recommenden SPDX license expression, see: https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license

[dataflake]

The correct SPDX license identifier is already in setup.py, see

RestrictedPython/setup.py

Line 30 in f208c0c

license='ZPL-2.1',

The trove classifier for the license still has informational value, even though it raises a warning. Even Copilot agrees: #303 (comment)

[icemac]

I'd prefer to get rid of these deprecation warnings, maybe the setuptools people know why they made such a big warning out of it.
There is also zopefoundation/meta#332 regarding this issue as a global solution. So I am closing the issue here referring to that one.