[Haskell] cabal and ghcconfigure.h

[Robert Dockins]

I've just run across a problem with my cabal build system -- I'm not yet sure 
if this is a cabal problem or a system configuration problem.

I've been developing a package on OSX using the ghc 6.4.1 and cabal from 
darwinports.  All is fine and dandy.  However, today I've sucked my darcs 
repo down to my machine at home (running Gentoo linux) and now my package 
won't build.  (this time with GHC 6.4.1 from portage and cabal 1.1.3)

It halts while apparently running an Alex generated lexer through CPP, with 
the error:

ghcconfig.h: No such file or directory

My GHC install has this file at /usr/lib/ghc-6.4.1/include, but it clearly 
isn't in the include path that cabal is using.

So the question is -- is this a cabal bug of some kind, or is the gentoo setup 
messed up some how?  How should I proceed?

Thanks
Rob Dockins