Its installation requires Cabal:
> which cabal
cabal: Command not found.
>
And Cabal is difficult to install, it reports that such and such package
versions are missing.
On the other hand, Cabal is, probably, present inside ghc-7.4.0.20111219,
somewhere in the installation directory. Thus I see its .a and .o files
in
~/ghc/7.4.1pre/inst0/lib/ghc-7.4.0.20111219/Cabal-1.14.0/