cabal-install use multiple config files?

I don't see a command-line switch to ask cabal-install to use a different config file. Is there an environment variable for it or something? I want to use the same cabal-install binary with three different installs of ghc and ghc-pkg to allow me to maintain my cross-compiler packages as well. -- Stephen Paul Weber, @singpolyma See http://singpolyma.net for how I prefer to be contacted edition right joseph