src/Pure/ML/ml_process.scala

     val session_heaps = store.session_heaps(session_background, logic = logic)
 
     val process =
       ML_Process(options, session_background, session_heaps,
         args = eval_args.toList, modes = modes, cwd = cwd, redirect = redirect)
+
     if (internal) process.result()
     else {
       process.result(
         progress_stdout = Output.writeln(_, stdout = true),
         progress_stderr = Output.writeln(_))