Cabal doesn't implement an option that the documentation says it does

[bos]

(Imported from Trac #99, reported by guest on 2006-11-20)

Hi, I'm attempting to get hsgnutls working on my machine. It uses Cabal for the installation but when I attempt to run:

runghc Setup.lhs build

I get an error about c2hs not existing. c2hs does exist on my machine and is findable in my path

$ c2hs --version
C->Haskell Compiler, version 0.13.6 "Pressing Forward", 18 May 2005

Now according to the documentation [here](http://www.haskell.org/cabal/release/latest/doc/users-guide/x606.html#setup-configure) I can use the option --with-c2hs=path to help Cabal find it, but it seems Cabal doesn't actually implement this option.