关于.pch Could not build module 'U

国庆期间好奇，升级到xcode 11.0，macOS Catalina .不说了，都是泪

之前的项目，就导致了头文件报错。整了好久，又是更新cocoapods 又是重装xcode。

总算是解决了，仅此记录。

1- Quit Xcode Totally

2- Delete this folder And Empty Trash

/Library/Developer/CommandLineTools

参考：https://stackoverflow.com/questions/52595744/could-not-build-module-uikit-after-upgrade-to-xcode-10-0