src/HOL/Library/adhoc_overloading.ML

     val args =
       raw_args
       |> map (apfst (const_name lthy))
       |> map (apsnd (map (read_term lthy)));
   in
-    Local_Theory.declaration {syntax = true, pervasive = false}
+    Local_Theory.declaration {syntax = true, pervasive = false, pos = Position.thread_data ()}
       (adhoc_overloading_cmd' add args) lthy
   end;
 
 val _ =
   Outer_Syntax.local_theory \<^command_keyword>\<open>adhoc_overloading\<close>