Add missing methods to PathEntryFinder

setuptools/command/editable_wheel.py

@@ -542,17 +542,23 @@ def _path_hook(cls, path):
             return cls
         raise ImportError
 
+    @classmethod
+    def _paths(cls, fullname):
+        # Ensure __path__ is not empty for the spec to be considered a namespace.
+        return NAMESPACES[fullname] or MAPPING.get(fullname) or [PATH_PLACEHOLDER]
+
     @classmethod
     def find_spec(cls, fullname, target=None):
         if fullname in NAMESPACES:
             spec = ModuleSpec(fullname, None, is_package=True)
-            paths = NAMESPACES[fullname] or MAPPING.get(fullname) or [PATH_PLACEHOLDER]
-            # ^ We have to ensure submodule_search_locations to not be empty for the
-            #   spec to be considered a namespace
-            spec.submodule_search_locations = paths
+            spec.submodule_search_locations = cls._paths(fullname)
             return spec
         return None
 
+    @classmethod
+    def find_module(cls, fullname):
+        return None
+
 
 def install():
     if not any(finder == _EditableFinder for finder in sys.meta_path):