PCH was compiled with module cac

PCH was compiled with module cache的原因可能是在切换工作环境的时候，Xcode自动缓存的路径和现在工作环境的路径不一致导致的。
解决方法如下：

1.Close your project or workspace.
2.In Finder: ⇧shift+⌘cmd+G
3.Paste: ~/Library/Developer/Xcode/DerivedData/
4.Delete the ModuleCache folder and empty trash.
5.Open up your project.
6.Clean: ⇧shift+⌘cmd+K
7.Build: ⌘cmd+B

删除完后可能会导致虚拟器出现The file “Logs” couldn’t be saved in the folder “Library” because a file with the same name already exists.

问题解决方法也很简单： iOS Simulator -> Reset Content and Settings...