protected void updateStatusInQueryDisplay() {
    if (queryDisplay != null) {
      queryDisplay.updateTaskStatus(this);
    }
  }
this can be set by the Task, to provide more info about the failure in TaskResult
where the Driver can find it.  This is checked if {@link Task#execute()}
returns non-0 code.
ql/src/java/org/apache/hadoop/hive/ql/exec/Task.java