src/Pure/PIDE/command.ML

         val tr =
           Position.setmp_thread_data (Position.id_only (Document_ID.print exec_id))
             (fn () =>
               read keywords thy master_dir init blobs_info span |> Toplevel.exec_id exec_id) ();
       in eval_state keywords span tr eval_state0 end;
-  in Eval {exec_id = exec_id, eval_process = Lazy.lazy process} end;
+  in Eval {exec_id = exec_id, eval_process = Lazy.lazy_name "Command.eval" process} end;
 
 end;
 
 
 (* print *)

             else print_error tr opt_context (fn () => print_fn tr st')
           end;
       in
         Print {
           name = name, args = args, delay = delay, pri = pri, persistent = persistent,
-          exec_id = exec_id, print_process = Lazy.lazy process}
+          exec_id = exec_id, print_process = Lazy.lazy_name "Command.print" process}
       end;
 
     fun bad_print name args exn =
       make_print name args {delay = NONE, pri = 0, persistent = false,
         strict = false, print_fn = fn _ => fn _ => Exn.reraise exn};