I recently updated app-emacs/haskell-mode to the latest ~x86 version, which is
2.1. I load my site-gentoo.el file every time I run emacs, but haskell-mode
wouldn't work properly until I added the following line to my ~/.emacs:
(load "/usr/share/emacs/site-lisp/haskell-mode/haskell-site-file")
As far as I can tell, the new versions of haskell-mode keep most of the
settings that had to be set manually (e.g. loading of ghci or hugs
interpreters), and as such something to the extent of the line above should be
added to the site-gentoo.el file.