Xcode 4.02 consistently hanging during build of large project

I am working on a large project. Whenever I tell 开发者_StackOverflow社区it to build, Xcode 4.02 hangs. Yeah, I should report the bug, and maybe it will be fixed someday. In the meantime, has anyone else encountered this difficulty? If so, how did you solve it?

The problem was that I was importing Foundation.h in the header of a C file.