Add warning for deprecated metadata fields

Author: abravalheri

docs/references/keywords.rst

@@ -85,11 +85,21 @@ extensions).
 ``url``
     A string specifying the URL for the package homepage.
 
+    .. warning::
+        ``url`` is deprecated as it generates the ``Home-page`` metadata.
+        Please use ``project_urls`` instead, with the relevant labels.
+        See :pep:`753`.
+
 .. _keyword/download_url:
 
 ``download_url``
     A string specifying the URL to download the package.
 
+    .. warning::
+        ``download_url`` is deprecated as it generates the ``Download-URL`` metadata.
+        Please use ``project_urls`` instead, with the relevant labels.
+        See :pep:`753`.
+
 .. _keyword/packages:
 
 ``packages``
@@ -257,14 +267,14 @@ extensions).
 
 ``requires``
    .. warning::
-      ``requires`` is superseded by ``install_requires`` and should not be used
-      anymore.
+      ``requires`` is deprecated and superseded by ``install_requires``.
+      It should not be used anymore.
 
 .. _keyword/obsoletes:
 
 ``obsoletes``
    .. warning::
-      ``obsoletes`` is currently ignored by ``pip``.
+      ``obsoletes`` is deprecated and currently ignored by ``pip``.
 
    List of strings describing packages which this package renders obsolete,
    meaning that the two projects should not be installed at the same time.
@@ -283,7 +293,7 @@ extensions).
 
 ``provides``
    .. warning::
-      ``provides`` is currently ignored by ``pip``.
+      ``provides`` is currently considered deprecated and is ignored by ``pip``.
 
    List of strings describing package- and virtual package names contained
    within this package.

setuptools/dist.py

@@ -231,6 +231,18 @@ def check_packages(dist, attr, value):
             )
 
 
+def _check_deprecated_metadata_field(
+    dist: Distribution, attr: str, value: object
+) -> None:
+    if value:
+        SetuptoolsDeprecationWarning.emit(
+            f"Deprecated usage of `{attr}` in setuptools configuration.",
+            see_docs=f"references/keywords.html#keyword-{attr.replace('_', '-')}",
+            due_date=(2027, 1, 25),
+            # Warning initially introduced in 14 Jan 2025
+        )
+
+
 if TYPE_CHECKING:
     # Work around a mypy issue where type[T] can't be used as a base: https://github.com/python/mypy/issues/10962
     from distutils.core import Distribution as _Distribution
@@ -294,6 +306,14 @@ class Distribution(_Distribution):
         'extras_require': dict,
     }
 
+    _DEPRECATED_FIELDS = (
+        "url",
+        "download_url",
+        "requires",
+        "provides",
+        "obsoletes",
+    )
+
     # Used by build_py, editable_wheel and install_lib commands for legacy namespaces
     namespace_packages: list[str]  #: :meta private: DEPRECATED
 
@@ -318,6 +338,9 @@ def __init__(self, attrs: MutableMapping[str, Any] | None = None) -> None:
         dist_attrs = {k: v for k, v in attrs.items() if k not in metadata_only}
         _Distribution.__init__(self, dist_attrs)
 
+        for attr in self._DEPRECATED_FIELDS:
+            _check_deprecated_metadata_field(self, attr, dist_attrs.get(attr))
+
         # Private API (setuptools-use only, not restricted to Distribution)
         # Stores files that are referenced by the configuration and need to be in the
         # sdist (e.g. `version = file: VERSION.txt`)

setuptools/tests/test_dist.py

@@ -5,7 +5,7 @@
 
 import pytest
 
-from setuptools import Distribution
+from setuptools import Distribution, SetuptoolsDeprecationWarning
 from setuptools.dist import check_package_data, check_specifier
 
 from .test_easy_install import make_nspkg_sdist
@@ -276,3 +276,22 @@ def test_dist_default_name(tmp_path, dist_name, package_dir, package_files):
     dist.set_defaults()
     assert dist.py_modules or dist.packages
     assert dist.get_name() == dist_name
+
+
+@pytest.mark.parametrize(
+    ("field", "value"),
+    [
+        ("requires", ["setuptools"]),
+        ("provides", ["setuptools"]),
+        ("obsoletes", ["setuptools"]),
+        ("url", "www.setuptools.com.br"),
+        ("download_url", "www.setuptools.com.br/42"),
+    ],
+)
+def test_deprecated_fields(tmpdir_cwd, field, value):
+    """See discussion in https://github.com/pypa/setuptools/issues/4797"""
+    attrs = {"name": "test", "version": "0.42", field: value}
+    match = f"Deprecated usage of `{field}`"
+    with pytest.warns(SetuptoolsDeprecationWarning, match=match):
+        dist = Distribution(attrs)
+        assert getattr(dist.metadata, field, None) == value