src/sage/misc/cython.py: Fix the workaround for setuptools_scm in the runtime env

Author: Matthias Koeppe

src/sage/misc/cython.py

@@ -421,15 +421,20 @@ def cython(filename, verbose=0, compile_message=False,
                         os.curdir)
 
     # This emulates running "setup.py build" with the correct options
-    dist = Distribution()
+    #
     # setuptools plugins considered harmful:
     # If build isolation is not in use and setuptools_scm is installed,
     # then its file_finders entry point is invoked, which we don't need.
     # And with setuptools_scm 8, we get more trouble:
     # LookupError: pyproject.toml does not contain a tool.setuptools_scm section
     # LookupError: setuptools-scm was unable to detect version ...
     # We just remove all handling of "setuptools.finalize_distribution_options" entry points.
-    dist._removed = staticmethod(lambda ep: True)
+    class Distribution_no_finalize_distribution_options(Distribution):
+        @staticmethod
+        def _removed(ep):
+            return True
+
+    dist = Distribution_no_finalize_distribution_options()
     dist.ext_modules = [ext]
     dist.include_dirs = includes
     buildcmd = dist.get_command_obj("build")