Hi, I'm try to make GHC head stably buildable with clang/wrapper on Mavericks because we cannot ask all Mavericks users to install apple-gcc or GCC. The last big item for me is integer-gmp. GHC head cannot be built with clang/wrapper if integer-gmp is used. (integer-simple is OK.) This is because "configure" of libgmp fails. Now I understand why this happens. The source of this problem is "/usr/bin/gcc" which is a wrapper for clang (not gcc actually). This cheats "configure" of libgmp. If we type "CC=clang ./configure", it works. The problem is how to specify "CC=clang" to configure of libgmp when we build GHC head. If we modified "libraries/integer-gmp/gmp/ghc.mk" manually, we can build GHC head. But I don't like this one since "make maintainer-clean" removes "ghc.mk". Any ideas? Ticket is here: https://ghc.haskell.org/trac/ghc/ticket/8497 --Kazu