Xcode 4 - clang error

Question

I\'m migrating from Xcode 3.5 to Xcode 4 and while I\'m trying to Archiving my app for AdHoc distribution.
I received this error

Precompile MyApp_Prefix.

Answer 1

I just had this problem with an instagram lib, my mistake was that i was importing the files to a target and compiled the other target. It gave me some headaches.