react-native bug -- xcrun error

react-native bug xcrun error SDK "xx" cannot be locateed 解决

os: mac os 10.14.1 

错误：

checking whether the C compiler works... no xcrun: error: SDK "iphoneos" cannot be located xcrun: error: SDK "iphoneos" cannot be located xcrun: error: SDK "iphoneos" cannot be located xcrun: error: unable to lookup item 'Path' in SDK 'iphoneos'

解决方案：

在终端执行  sudo xcode-select --switch /Applications/Xcode.app