当我运行 ionic serve 时，它会构建应用程序但服务器没有运行。这是线索：
Starting app-scripts server: --address 0.0.0.0 --port 8100 --livereload-port 35729
--dev-logger-port 53703 --nobrowser - Ctrl+C to cancel
[17:55:35] watch started ...
[17:55:35] build dev started ...
[17:55:36] clean started ...
[17:55:36] clean finished in 2 ms
[17:55:36] copy started ...
[17:55:36] deeplinks started ...
[17:55:37] deeplinks finished in 589 ms
[17:55:37] transpile started ...
[17:55:44] transpile finished in 7.38 s
[17:55:44] preprocess started ...
[17:55:44] copy finished in 8.56 s
[17:55:44] preprocess finished in 206 ms
[17:55:44] webpack started ...
在 webpack 启动之后，cli 就退出了，我看到了正常的终端提示。
尝试 npm run ionic:serve 命令会导致此错误：
TypeError: Cannot read property 'substr' of undefined
到目前为止，我已经重新安装了 ionic，结果相同。有点不知道怎么处理这个...