fix #918: remove the need for importlib_metadata in general (broke python<=3.9)

Author: RonnyPfannschmidt

CHANGELOG.rst

@@ -1,3 +1,8 @@
+v8.0.3
+======
+
+* fix #918 for good - remove external importlib-metadata to avoid source only loop
+
 v8.0.2
 ======
 

pyproject.toml

@@ -3,11 +3,9 @@
 [build-system]
 build-backend = "_own_version_helper"
 requires = [
-  'importlib-metadata>=4.6; python_version < "3.10"',
   "rich",
   "setuptools>=61",
   'tomli; python_version < "3.11"',
-  'typing_extensions; python_version < "3.8"',
 ]
 backend-path = [
   ".",
@@ -42,7 +40,6 @@ dynamic = [
   "version",
 ]
 dependencies = [
-  'importlib-metadata>=4.6; python_version < "3.10"',
   "packaging>=20",
   "setuptools",
   'tomli>=1; python_version < "3.11"',

src/setuptools_scm/_entrypoints.py

@@ -6,7 +6,6 @@
 from typing import cast
 from typing import Iterator
 from typing import overload
-from typing import Protocol
 from typing import TYPE_CHECKING
 
 from . import _log
@@ -17,15 +16,32 @@
     from ._config import Configuration, ParseFunction
 
 
-log = _log.log.getChild("entrypoints")
+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)
 
-class EntrypointProtocol(Protocol):
-    name: str
-    value: str
+    def entry_points(group: str) -> EntryPoints:
+        return EntryPoints(legacy_entry_points()[group])
 
-    def load(self) -> Any:
-        pass
+else:
+    from importlib.metadata import entry_points, EntryPoints
+
+
+log = _log.log.getChild("entrypoints")
 
 
 def version_from_entrypoint(
@@ -43,27 +59,11 @@ def version_from_entrypoint(
     return None
 
 
-if sys.version_info[:2] < (3, 10):
-    from importlib_metadata import entry_points
-    from importlib_metadata import EntryPoint
-else:
-    from importlib.metadata import entry_points
-    from importlib.metadata import EntryPoint
-
-
-def iter_entry_points(
-    group: str, name: str | None = None
-) -> Iterator[EntrypointProtocol]:
-    eps = entry_points(group=group)
-    res = (
-        eps
-        if name is None
-        else eps.select(  # type: ignore [no-untyped-call]
-            name=name,
-        )
-    )
+def iter_entry_points(group: str, name: str | None = None) -> Iterator[EntryPoint]:
+    eps: EntryPoints = entry_points(group=group)
+    res = eps if name is None else eps.select(name=name)
 
-    return cast(Iterator[EntrypointProtocol], iter(res))
+    return iter(res)
 
 
 def _get_ep(group: str, name: str) -> Any | None:
@@ -76,7 +76,7 @@ def _get_ep(group: str, name: str) -> Any | None:
 
 def _get_from_object_reference_str(path: str, group: str) -> Any | None:
     # todo: remove for importlib native spelling
-    ep: EntrypointProtocol = EntryPoint(path, path, group)
+    ep = EntryPoint(path, path, group)
     try:
         return ep.load()
     except (AttributeError, ModuleNotFoundError):

src/setuptools_scm/discover.py

@@ -47,7 +47,7 @@ def match_entrypoint(root: _t.PathT, name: str) -> bool:
 
 def iter_matching_entrypoints(
     root: _t.PathT, entrypoint: str, config: Configuration
-) -> Iterable[_entrypoints.EntrypointProtocol]:
+) -> Iterable[_entrypoints.EntryPoint]:
     """
     Consider different entry-points in ``root`` and optionally its parents.
     :param root: File path.