For some reason, I can't get runghc to work with GHC HEAD. Compiling with ghc-stage2 and running ghc-stage2 --interactive both work okay, it's just runghc that doesn't want to cooperate for some reason:

    $ .\ghc\inplace\bin\runghc.exe Z.hs
    runghc.exe: C:\Users\ryanscot\Documents\Software\ghc\inplace\bin\ghc: rawSystem: does not exist (No such file or directory)