xcrun: error: active developer path ("/Applications/Xcode 6.2.app/Contents/Developer") does not exist, usexcode-select --switch path/to/Xcode.appto specify the Xcode that you wish to use for command line developer tools (or seeman xcode-select)
附:我上面出错是因为我的xcode6.2被我删了
解决方法:
终端执行sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer命令,然后再输入一次系统的密码,完成。