Xcode version 4.6.2 (4H1003) compiler error

Question

I just updated to Xcode version 4.6.2 (4H10003) and tried to run a previously working application project in the simulator and received the following error and the build failed.

PCH file built from a different branch ((clang-425.0.27)) than the compiler ((clang-425.0.28))

What went wrong and how can it be fixed?

Answer 1

Do a Clean of the project; hold Option so that you are cleaning out the whole build folder and intermediates. You might have to quit Xcode and throw away the whole contents of the DerivedData folder by hand in the Finder, as I describe here: How to Empty Caches and Clean All Targets Xcode 4

Answer 2

Go to your project's Build Settings, find a setting named Precompiled Headers Cache Path, then delete that folder