You are right. But I'm not happy with cabal installing a lot of different version of packages. I think that completing the archhaskell repository is the way to go. Pacman is much more better.

As for hakyll, you can find a compiled package here: http://archhaskell.mynerdside.com/haskell-extra/x86_64/. This version is linked with main [haskell] repository, so it's not the newest one as it would need a newer blaze-html.

Hope this can help.

Cheers,

Fabio