fatal error: malformed or corrupted AST file - Xcode

Question

I get this error when building my app in the latest version of Xcode:

fatal error: malformed or corrupted AST file: \'Unable to load module \"/Users

Answer 1

In my case, I accidentally modified NSURLConnection.h. Xcode complained about cache at path

/var/folders/p6/fk2rmf017sn2d_gds6dtqr6hrst8b2/C/com.apple.DeveloperTools/5.0.2-5A3005/Xcode/5.0.2-5A3005/Xcode/ModuleCache/XWWWZ5ED888F

I finally found the steps to fix it:

1. Quit Xcode
2. Delete the upper "5.0.2-5A3005" at /var/folders/p6/fk2rmf017sn2d_gds6dtqr6hrst8b2/C/com.apple.DeveloperTools/5.0.2-5A3005

When Xcode restarted, it regenerated that folder and everything in it.