Address Barry's review

Author: vstinner

Lib/site.py

@@ -254,7 +254,6 @@ class StartupState:
         '_path_entries',
         '_importexecs',
         '_entrypoints',
-        '_sitedir',
     )
 
     def __init__(self, known_paths=None):
@@ -287,7 +286,6 @@ def __init__(self, known_paths=None):
         # when an entry fails.
         self._importexecs = {}
         self._entrypoints = {}
-        self._sitedir = None
 
     def addsitedir(self, sitedir):
         """Add a site directory and accumulate its .pth and .start startup data.
@@ -399,7 +397,6 @@ def _read_pth_file(self, sitedir, name):
         accepted paths are added to it so that subsequent .pth files in
         the same batch don't add them more than once.
         """
-        self._sitedir = sitedir
 
         lines, filename = _read_pthstart_file(sitedir, name, ".pth")
         if lines is None:
@@ -504,16 +501,16 @@ def _extend_syspath(self):
                 )
 
     def _exec_imports(self):
-        # Inject 'sitedir' local variable in the current frame for
-        # compatibility with Python 3.14. Especially, "-nspkg.pth" files
-        # generated by setuptools use: sys._getframe(1).f_locals['sitedir'].
-        sitedir = self._sitedir
-
         # For each `import` line we've seen in a .pth file, exec() it in
         # order, unless the .pth has a matching .start file in this same
         # batch.  In that case, PEP 829 says the import lines are
         # suppressed in favor of the .start's entry points.
         for filename, imports in self._importexecs.items():
+            # Inject 'sitedir' local variable in the current frame for
+            # compatibility with Python 3.14. Especially, "-nspkg.pth" files
+            # generated by setuptools use: sys._getframe(1).f_locals['sitedir'].
+            sitedir = os.path.dirname(filename)
+
             # Given "/path/to/foo.pth", check whether "/path/to/foo.start" was
             # registered in this same batch.
             name, dot, pth = filename.rpartition(".")

Lib/test/test_site.py

@@ -234,11 +234,10 @@ def test_addsitedir_hidden_file_attribute(self):
             self.assertIn(pth_file.base_dir, sys.path)
 
     def test_sitedir_variable(self):
-        # gh-149671: Provide 'sitedir' local variable for compatibility with
-        # Python 3.14
+        # gh-149671: setuptools use of `-nspkg.pth` files in Python < 3.15.
         code = '; '.join((
+            # Code used by "-nspkg.pth" files generated by setuptools.
             "import sys",
-            # Code used by "-nspkg.pth" files generated by setuptools
             "sitedir = sys._getframe(1).f_locals['sitedir']",
             "print(sitedir)",
         ))

Misc/NEWS.d/next/Library/2026-06-11-11-52-23.gh-issue-149671.6Rpr5r.rst

@@ -1,3 +1,3 @@
-Restore compatibility with setuptools ``nspkg.pth`` files in the :mod:`site`
+Restore compatibility with setuptools ``-nspkg.pth`` files in the :mod:`site`
 module. Inject ``sitedir`` variable in the frame which executes pth code.
 Patch by Victor Stinner.