I want to play a bit with Template Haskell, so I downloaded a cvs snapshot (ghc-5.05.20030123.tar.gz) and tried to compile it on my mac (OSX 10.2). I figured out that I needed a stage2 or stage3 compiler to get TH working, so I tried 'make stage3' . GHC started to compile itself three times. At lot of hours later it finished. Unfortunately, when I tried run the thing on a Prinf example, I got the following message. compiler/stage3-> ./ghc-inplace -c Printf.hs -fglasgow-exts -package haskell-src Template Haskell bracket illegal in a stage-1 compiler [| \s -> s |] The thing in"compiler/stage3" was just a stage-1 compiler, so ghc had achieved nothing useful after re-compiling three times :-( The problem is that GHCi support is not turned on for MacOSX. I guess GHCi is used to do compile-time evaluation of code for TH. In file "mk/config.mk.in" it says: # Include GHCi in the compiler. Default to NO for the time being. ifneq "$(findstring $(HostOS_CPP), mingw32 cygwin32 linux solaris2 freebsd netbsd openbsd)" "" GhcWithInterpreter=YES else GhcWithInterpreter=NO endif In the list of supported systems MacOSX is missing. After adding "darwin" to this list, and waiting for hours, I got a working TH-compiler. Can someone add OSX("darwin") to the "mk/config.mk.in" file? It would also be nice to get a warning if one tries to compile a stage-(N>1) compiler without GHCi support. Cheers, Arthur