testing current 6-4-branch

[Pavel Zolnikov]

> The GHC 6.4 branch does not have hs-source-dirs.  You need to checkout
> the HEAD to get it (but bear in mind that the HEAD is likely to be more
> unstable than the 6.4 branch).

Or instead of using unstable ghc branch you can try using unstable cabal (1.0.1):

darcs get http://cvs.haskell.org/darcs/cabal
make install
ghc-pkg unregister Cabal-1.0

Hope this helps,
Pavel.