worker.stderr
这是包含工作线程内写入 process.stderr 的数据的可读流。
如果 stderr: true 没有传给 Worker 构造函数，则数据将通过管道传输到父线程的 process.stderr 流。
This is a readable stream which contains data written to process.stderr
inside the worker thread. If stderr: true was not passed to the
Worker constructor, then data is piped to the parent thread's
process.stderr stream.