GHC 7 compiles fine, but there's an additional warning during linking.

$ system_profiler SPSoftwareDataType | grep "System Version"

System Version: Mac OS X 10.6.7 (10J869)

$ ghc --version

The Glorious Glasgow Haskell Compilation System, version 7.0.2

$ cat hello.hs

#!/usr/bin/env runhaskell

module Main where

main :: IO ()

main = putStrLn "Hello World"

$ ghc --make hello.hs

[1 of 1] Compiling Main ( hello.hs, hello.o )

Linking hello ...

ld: warning: -read_only_relocs cannot be used with x86_64

$ ./hello

Hello World

Cheers,

Andrew Pennebaker