src/Pure/Concurrent/future.ML

   res |> Exn.map_exn (fn exn =>
     let val exec_id =
       (case Position.id_of pos of
         NONE => []
       | SOME id => [(Markup.exec_idN, id)])
-    in Par_Exn.identify exec_id exn end);
+    in Exn_Properties.identify exec_id exn end);
 
 fun assign_result group result res =
   let
     val _ = Single_Assignment.assign result res
       handle exn as Fail _ =>