use importlib_metadata on python <3.10

fixes #1013 by no longer reporting duplicate distributions
the bugfix was included in python3.10 via importlib_metadata 4.6

Author: RonnyPfannschmidt

pyproject.toml

@@ -5,6 +5,7 @@ build-backend = "_own_version_helper:build_meta"
 requires = [
   "setuptools>=61",
   'tomli<=2.0.2; python_version < "3.11"',
+  'importlib-metadata>=4.6; python_version < "3.10"',
 ]
 backend-path = [
   ".",
@@ -43,9 +44,10 @@ dynamic = [
 dependencies = [
   "packaging>=20",
   # https://github.com/pypa/setuptools-scm/issues/1112 - re-pin in a breaking release
-  "setuptools", # >=61",
+  "setuptools >= 61",
   'tomli>=1; python_version < "3.11"',
   'typing-extensions; python_version < "3.10"',
+  'importlib-metadata>=4.6; python_version < "3.10"',
 ]
 [project.optional-dependencies]
 docs = [
@@ -69,38 +71,49 @@ test = [
 ]
 toml = [
 ]
+
 [project.urls]
 documentation = "https://setuptools-scm.readthedocs.io/"
 repository = "https://github.com/pypa/setuptools-scm/"
+
 [project.entry-points."distutils.setup_keywords"]
 use_scm_version = "setuptools_scm._integration.setuptools:version_keyword"
+
 [project.entry-points."pipx.run"]
 setuptools-scm = "setuptools_scm._cli:main"
 setuptools_scm = "setuptools_scm._cli:main"
+
 [project.entry-points."setuptools.file_finders"]
 setuptools_scm = "setuptools_scm._file_finders:find_files"
+
 [project.entry-points."setuptools.finalize_distribution_options"]
 setuptools_scm = "setuptools_scm._integration.setuptools:infer_version"
+
 [project.entry-points."setuptools_scm.files_command"]
 ".git" = "setuptools_scm._file_finders.git:git_find_files"
 ".hg" = "setuptools_scm._file_finders.hg:hg_find_files"
+
 [project.entry-points."setuptools_scm.files_command_fallback"]
 ".git_archival.txt" = "setuptools_scm._file_finders.git:git_archive_find_files"
 ".hg_archival.txt" = "setuptools_scm._file_finders.hg:hg_archive_find_files"
+
 [project.entry-points."setuptools_scm.local_scheme"]
 dirty-tag = "setuptools_scm.version:get_local_dirty_tag"
 no-local-version = "setuptools_scm.version:get_no_local_node"
 node-and-date = "setuptools_scm.version:get_local_node_and_date"
 node-and-timestamp = "setuptools_scm.version:get_local_node_and_timestamp"
+
 [project.entry-points."setuptools_scm.parse_scm"]
 ".git" = "setuptools_scm.git:parse"
 ".hg" = "setuptools_scm.hg:parse"
+
 [project.entry-points."setuptools_scm.parse_scm_fallback"]
 ".git_archival.txt" = "setuptools_scm.git:parse_archival"
 ".hg_archival.txt" = "setuptools_scm.hg:parse_archival"
 PKG-INFO = "setuptools_scm.fallbacks:parse_pkginfo"
 "pyproject.toml" = "setuptools_scm.fallbacks:fallback_version"
 "setup.py" = "setuptools_scm.fallbacks:fallback_version"
+
 [project.entry-points."setuptools_scm.version_scheme"]
 "calver-by-date" = "setuptools_scm.version:calver_by_date"
 "guess-next-dev" = "setuptools_scm.version:guess_next_dev_version"
@@ -133,7 +146,7 @@ order-by-type = true
 ignore = ["PP305", "GH103", "GH212", "MY100", "PC111", "PC160", "PC170", "PC180", "PC901"]
 
 [tool.pytest.ini_options]
-minversion = "7"
+minversion = "8"
 testpaths = ["testing"]
 filterwarnings = [
   "error",

src/setuptools_scm/_entrypoints.py

@@ -17,28 +17,12 @@
     from ._config import Configuration
     from ._config import ParseFunction
 
-
-from importlib.metadata import EntryPoint as EntryPoint
-
 if sys.version_info[:2] < (3, 10):
-    from importlib.metadata import entry_points as legacy_entry_points
-
-    class EntryPoints:
-        _groupdata: list[EntryPoint]
-
-        def __init__(self, groupdata: list[EntryPoint]) -> None:
-            self._groupdata = groupdata
-
-        def select(self, name: str) -> EntryPoints:
-            return EntryPoints([x for x in self._groupdata if x.name == name])
-
-        def __iter__(self) -> Iterator[EntryPoint]:
-            return iter(self._groupdata)
-
-    def entry_points(group: str) -> EntryPoints:
-        return EntryPoints(legacy_entry_points()[group])
-
+    from importlib_metadata import EntryPoint as EntryPoint
+    from importlib_metadata import EntryPoints
+    from importlib_metadata import entry_points
 else:
+    from importlib.metadata import EntryPoint as EntryPoint
     from importlib.metadata import EntryPoints
     from importlib.metadata import entry_points