Merge pull request #4997 from pypa/feature/remove-more-pkg_resources

Remove pkg_resources usage from installer (and more)

Author: jaraco

newsfragments/4997.feature.rst

@@ -0,0 +1 @@
+Removed usage of pkg_resources from installer. Set an official deadline on the installer deprecation to 2025-10-31.

setuptools/_normalization.py

@@ -36,7 +36,6 @@ def safe_name(component: str) -> str:
     >>> safe_name("hello_world")
     'hello_world'
     """
-    # See pkg_resources.safe_name
     return _UNSAFE_NAME_CHARS.sub("-", component)
 
 
@@ -81,7 +80,6 @@ def best_effort_version(version: str) -> str:
     >>> best_effort_version("42.+?1")
     '42.dev0+sanitized.1'
     """
-    # See pkg_resources._forgiving_version
     try:
         return safe_version(version)
     except packaging.version.InvalidVersion:

setuptools/_path.py

@@ -39,11 +39,20 @@ def same_path(p1: StrPath, p2: StrPath) -> bool:
     return normpath(p1) == normpath(p2)
 
 
+def _cygwin_patch(filename: StrPath):  # pragma: nocover
+    """
+    Contrary to POSIX 2008, on Cygwin, getcwd (3) contains
+    symlink components. Using
+    os.path.abspath() works around this limitation. A fix in os.getcwd()
+    would probably better, in Cygwin even more so, except
+    that this seems to be by design...
+    """
+    return os.path.abspath(filename) if sys.platform == 'cygwin' else filename
+
+
 def normpath(filename: StrPath) -> str:
     """Normalize a file/dir name for comparison purposes."""
-    # See pkg_resources.normalize_path for notes about cygwin
-    file = os.path.abspath(filename) if sys.platform == 'cygwin' else filename
-    return os.path.normcase(os.path.realpath(os.path.normpath(file)))
+    return os.path.normcase(os.path.realpath(os.path.normpath(_cygwin_patch(filename))))
 
 
 @contextlib.contextmanager

setuptools/_reqs.py

@@ -37,6 +37,6 @@ def parse(strs: _StrOrIter) -> Iterator[Requirement]: ...
 def parse(strs: _StrOrIter, parser: Callable[[str], _T]) -> Iterator[_T]: ...
 def parse(strs: _StrOrIter, parser: Callable[[str], _T] = parse_req) -> Iterator[_T]:  # type: ignore[assignment]
     """
-    Replacement for ``pkg_resources.parse_requirements`` that uses ``packaging``.
+    Parse requirements.
     """
     return map(parser, parse_strings(strs))

setuptools/dist.py

@@ -46,8 +46,6 @@
 if TYPE_CHECKING:
     from typing_extensions import TypeAlias
 
-    from pkg_resources import Distribution as _pkg_resources_Distribution
-
 
 __all__ = ['Distribution']
 
@@ -761,9 +759,7 @@ def parse_config_files(
         self._finalize_license_expression()
         self._finalize_license_files()
 
-    def fetch_build_eggs(
-        self, requires: _StrOrIter
-    ) -> list[_pkg_resources_Distribution]:
+    def fetch_build_eggs(self, requires: _StrOrIter) -> list[metadata.Distribution]:
         """Resolve pre-setup requirements"""
         from .installer import _fetch_build_eggs
 

setuptools/installer.py

@@ -5,20 +5,18 @@
 import subprocess
 import sys
 import tempfile
-from functools import partial
-from typing import TYPE_CHECKING
+
+import packaging.requirements
+import packaging.utils
 
 from . import _reqs
-from ._reqs import _StrOrIter
+from ._importlib import metadata
 from .warnings import SetuptoolsDeprecationWarning
 from .wheel import Wheel
 
 from distutils import log
 from distutils.errors import DistutilsError
 
-if TYPE_CHECKING:
-    from pkg_resources import Distribution
-
 
 def _fixup_find_links(find_links):
     """Ensure find-links option end-up being a list of strings."""
@@ -37,25 +35,30 @@ def fetch_build_egg(dist, req):
     return _fetch_build_egg_no_warn(dist, req)
 
 
-def _fetch_build_eggs(dist, requires: _StrOrIter) -> list[Distribution]:
-    import pkg_resources  # Delay import to avoid unnecessary side-effects
-
+def _fetch_build_eggs(dist, requires: _reqs._StrOrIter) -> list[metadata.Distribution]:
     _DeprecatedInstaller.emit(stacklevel=3)
     _warn_wheel_not_available(dist)
 
-    resolved_dists = pkg_resources.working_set.resolve(
-        _reqs.parse(requires, pkg_resources.Requirement),  # required for compatibility
-        installer=partial(_fetch_build_egg_no_warn, dist),  # avoid warning twice
-        replace_conflicting=True,
+    needed_reqs = (
+        req for req in _reqs.parse(requires) if not req.marker or req.marker.evaluate()
     )
+    resolved_dists = [_fetch_build_egg_no_warn(dist, req) for req in needed_reqs]
     for dist in resolved_dists:
-        pkg_resources.working_set.add(dist, replace=True)
+        # dist.locate_file('') is the directory containing EGG-INFO, where the importabl
+        # contents can be found.
+        sys.path.insert(0, str(dist.locate_file('')))
     return resolved_dists
 
 
-def _fetch_build_egg_no_warn(dist, req):  # noqa: C901  # is too complex (16)  # FIXME
-    import pkg_resources  # Delay import to avoid unnecessary side-effects
+def _dist_matches_req(egg_dist, req):
+    return (
+        packaging.utils.canonicalize_name(egg_dist.name)
+        == packaging.utils.canonicalize_name(req.name)
+        and egg_dist.version in req.specifier
+    )
+
 
+def _fetch_build_egg_no_warn(dist, req):  # noqa: C901  # is too complex (16)  # FIXME
     # Ignore environment markers; if supplied, it is required.
     req = strip_marker(req)
     # Take easy_install options into account, but do not override relevant
@@ -80,9 +83,11 @@ def _fetch_build_egg_no_warn(dist, req):  # noqa: C901  # is too complex (16)  #
     if dist.dependency_links:
         find_links.extend(dist.dependency_links)
     eggs_dir = os.path.realpath(dist.get_egg_cache_dir())
-    environment = pkg_resources.Environment()
-    for egg_dist in pkg_resources.find_distributions(eggs_dir):
-        if egg_dist in req and environment.can_add(egg_dist):
+    cached_dists = metadata.Distribution.discover(
+        path=glob.glob(f'{eggs_dir}/*.egg/EGG-INFO')
+    )
+    for egg_dist in cached_dists:
+        if _dist_matches_req(egg_dist, req):
             return egg_dist
     with tempfile.TemporaryDirectory() as tmpdir:
         cmd = [
@@ -112,12 +117,7 @@ def _fetch_build_egg_no_warn(dist, req):  # noqa: C901  # is too complex (16)  #
         wheel = Wheel(glob.glob(os.path.join(tmpdir, '*.whl'))[0])
         dist_location = os.path.join(eggs_dir, wheel.egg_name())
         wheel.install_as_egg(dist_location)
-        dist_metadata = pkg_resources.PathMetadata(
-            dist_location, os.path.join(dist_location, 'EGG-INFO')
-        )
-        return pkg_resources.Distribution.from_filename(
-            dist_location, metadata=dist_metadata
-        )
+        return metadata.Distribution.at(dist_location + '/EGG-INFO')
 
 
 def strip_marker(req):
@@ -126,20 +126,16 @@ def strip_marker(req):
     calling pip with something like `babel; extra == "i18n"`, which
     would always be ignored.
     """
-    import pkg_resources  # Delay import to avoid unnecessary side-effects
-
     # create a copy to avoid mutating the input
-    req = pkg_resources.Requirement.parse(str(req))
+    req = packaging.requirements.Requirement(str(req))
     req.marker = None
     return req
 
 
 def _warn_wheel_not_available(dist):
-    import pkg_resources  # Delay import to avoid unnecessary side-effects
-
     try:
-        pkg_resources.get_distribution('wheel')
-    except pkg_resources.DistributionNotFound:
+        metadata.distribution('wheel')
+    except metadata.PackageNotFoundError:
         dist.announce('WARNING: The wheel package is not available.', log.WARN)
 
 
@@ -149,4 +145,4 @@ class _DeprecatedInstaller(SetuptoolsDeprecationWarning):
     Requirements should be satisfied by a PEP 517 installer.
     If you are using pip, you can try `pip install --use-pep517`.
     """
-    # _DUE_DATE not decided yet
+    _DUE_DATE = 2025, 10, 31

setuptools/tests/test_dist.py

@@ -56,7 +56,7 @@ def sdist_with_index(distname, version):
         dist = Distribution()
         dist.parse_config_files()
         resolved_dists = [dist.fetch_build_egg(r) for r in reqs]
-    assert [dist.key for dist in resolved_dists if dist] == reqs
+    assert [dist.name for dist in resolved_dists if dist] == reqs
 
 
 EXAMPLE_BASE_INFO = dict(