code: function fatal_error(msg) {
      has_exited = true;
      ui_disabled = true;
      GlkOte.error(msg);
      var dataobj = { type: 'update', gen: event_generation, disable: true };
      dataobj.input = [];
      GlkOte.update(dataobj);
  }
docs: /* This is the handler for a VM fatal error. (Not for an error in our own
  library!) We display the error message, and then push a final display
  update, which kills all input fields in all windows.