https://bugs.freedesktop.org/show_bug.cgi?id=49110
--- Comment #1 from Tom Stellard tstellar@gmail.com 2012-04-24 16:04:18 PDT --- I think this happens when you build Mesa with debugging enabled and LLVM without it enabled. It's still a bug though. For now, you could try building a debug version of both Mesa and LLVM. I think that will fix it.