Fixes #8568. Ignore TypeError from getslots in isslotsattribute

CHANGES

@@ -18,6 +18,7 @@ Bugs fixed
 
 * #8559: autodoc: AttributeError is raised when using forward-reference type
   annotations
+* #8568: autodoc: TypeError is raised on checking slots attribute
 
 Testing
 --------

sphinx/ext/autodoc/__init__.py

@@ -2114,7 +2114,7 @@ def isslotsattribute(self) -> bool:
                 return True
             else:
                 return False
-        except (AttributeError, ValueError):
+        except (AttributeError, ValueError, TypeError):
             return False
 
     def import_object(self, raiseerror: bool = False) -> bool:

sphinx/util/inspect.py

@@ -187,6 +187,7 @@ def getslots(obj: Any) -> Optional[Dict]:
 
     Return None if gienv *obj* does not have __slots__.
     Raises AttributeError if given *obj* raises an error on accessing __slots__.
+    Raises TypeError if given *obj* is not a class.
     Raises ValueError if given *obj* have invalid __slots__.
     """
     if not inspect.isclass(obj):