I've just run the ghc-clang-wrapper script (from https://gist.github.com/tibbe/8448715) to try to get GHC 7.6.3 (part of Haskell Platform 2013-2.0.0) working with XCode 5.0.2 on a MacOS 10.8.5 machine. Things look good, but I have two questions: Question 1: How do I know this worked? I tested it by modifying a package that I'm writing so that it requires CPP to build correctly, and successfully built it with "cabal clean; cabal configure; cabal build". (More details available on request.) Does that mean I'm in good shape? (I'm asking because I was never entirely clear on what the incompatibility was; all I know is that it has something to do with cpp.) Question 2: Is there any harm in adding -Wno-return-type to extraClangArgs in ghc-clang-wrapper? This silences an annoying but apparently harmless warning I get from "cabal configure". Thanks, Richard