xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun

Have you upgraded to OS X El Cap­i­tan from App Store ?

Have you sud­denly started get­ting the fol­low­ing error in your project?

xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun

If yes, then here is the solution

xcode-select --install

Mac最新场景下安装Xcode时已经没有Command Line了，需要单独安装。根据提示在使用命令xcode-select --install 安装时最后结果是不能安装该软件。
所以只要执行：
xcode-select --install 1
就可以了。解决问题