add debugging

Author: pablogsal

Modules/_testexternalinspection.c

@@ -713,7 +713,7 @@ parse_task_name(
     }
 
     if(!(flags & Py_TPFLAGS_UNICODE_SUBCLASS)) {
-        PyErr_SetString(PyExc_RuntimeError, "Invalid task name object");
+        PyErr_Format(PyExc_RuntimeError, "Task name is neither a string nor a long: %d", flags);
         return NULL;
     }