今天我用 create-react-native-app 创建了一个新项目，在安装了依赖项之后，CRNA说要用 expo start 开始你的项目，运行这个命令之后，所有东西看起来都很好并且打开了一个chrome页面 localhost:19002 但是一分钟之后这个页面被停止并且在控制台中它说：

[12:26:47] Starting project at D:\Try\eleventh
  [12:27:13] Warning: Problem validating app.json: Unable to perform cache 
  refresh for C:\Users\Mohammad\AppData\Local\Expo\schema-30.0.0.json: 
  Error: connect ETIMEDOUT 35.202.142.166:443.
  [12:27:39] Starting Metro Bundler on port 19001.
  [12:27:39] Metro Bundler ready.
  [12:27:40] Opening on Android device
  [12:27:40] Successfully ran `adb reverse`. Localhost URLs should work on 
  the connected Android device.
  [12:27:44] Tunnel ready.
  [12:27:44] Expo DevTools is running at http://localhost:19002
  [12:27:44] Opening DevTools in the browser... (press shift-d to disable)

   exp://192.168.89.2:19000





























    To run the app with live reloading, choose one of:
   [12:27:44] wrapItem(...).trimStart is not a function
   [12:27:44] Set EXPO_DEBUG=true in your env to view the stack trace.

正如你所看到的那样：

wrapItem(...).trimStart is not a function

这是一些可能有用的信息：

create-react-native-app version：2.0.2

节点版本：v8.11.3

世博会版本：2.2.0

npm版本：6.4.0

纱线版本：1.10.1

react-native expo create-react-native-app