reactjs - 尝试运行npm start命令时出错

Question

我正在尝试创建一个React项目，我先运行npx create-react-app my-app然后运行cd my-app，但是当我运行npm start时
已显示此错误:

> my-app@0.1.0 start C:\Users\USER\my-app
> react-scripts start

i ｢wds｣: Project is running at http://192.168.137.1/
i ｢wds｣: webpack output is served from
i ｢wds｣: Content not from webpack is served from C:\Users\HAMOOD\my-app\public
i ｢wds｣: 404s will fallback to /
Starting the development server...

events.js:292
      throw er; // Unhandled 'error' event
      ^

Error: spawn powershell ENOENT
    at Process.ChildProcess._handle.onexit (internal/child_process.js:267:19)
    at onErrorNT (internal/child_process.js:469:16)
    at processTicksAndRejections (internal/process/task_queues.js:84:21)
Emitted 'error' event on ChildProcess instance at:
    at Process.ChildProcess._handle.onexit (internal/child_process.js:273:12)
    at onErrorNT (internal/child_process.js:469:16)
    at processTicksAndRejections (internal/process/task_queues.js:84:21) {
  errno: 'ENOENT',
  code: 'ENOENT',
  syscall: 'spawn powershell',
  path: 'powershell',
  spawnargs: [
    '-NoProfile',
    '-NonInteractive',
    '–ExecutionPolicy',
    'Bypass',
    '-EncodedCommand',
    'UwB0AGEAcgB0ACAAIgBgACIAaAB0AHQAcAA6AC8ALwBsAG8AYwBhAGwAaABvAHMAdAA6ADMAMAAwADAAYAAiACIA'
  ]
}
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! my-app@0.1.0 start: `react-scripts start`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the my-app@0.1.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\HAMOOD\AppData\Roaming\npm-cache\_logs\2020-08-23T13_09_04_330Z-debug.log

我试图删除node_modules，然后再次安装了它，但是仍然发生相同的问题

Answer 1

我找到了一些可能的解决方案。似乎您使用的是Powershell，请首先检查您的Powershell是否为％SystemRoot％/system32/WindowsPowerShell/v1.0。之后，以管理员身份打开powershell并编写

Set-ExecutionPolicy Unrestricted -Scope CurrentUser -Force

如果powershell出现问题，应该会有所帮助。或者，有时在cra dev服务器尝试打开W​​eb浏览器时可能是错误。 github上的某人说这对他有帮助:

This error stems from the fact that CRA tries to open your browser:In order to skip opening the browser, addBROWSER=noneto your .env or .env.local file

另一种方法是使用这些命令将项目的 react 脚本降级

npm install react-scripts@2.1.8
npm start