PCH file built from a different branch ((clang-425.0.27)) than the compiler ((clang-425.0.28))
Project builds ok in XCode. I've tried a Clean and Build, same result.
Weird... After a number of runs on XCode it now magically works.
It was caused by incompatible compiler caches in Xcode 4.6.1 and 4.6.2.
You may see it again on other projects but it should go away after rebuild.