[Haskell-cafe] a question about cabal files

Hi cafe, I'm developing a library. In this package, some tools for development are included. I would like to compile these tools when I'm developing but I don't want users to compile them. Are there any ways to express such modes in cabal files? ("Executable" cannot be located under "if".) Or should I prepare a separated package for the development tools? Regards, --Kazu