---------- Mensagem encaminhada ----------
De: "Fábio Roberto Teodoro" <fr.teodoro@gmail.com>
Data: 04/08/2015 11:04
Assunto: latest Haskell Platform build fails
Para: <beginner@haskell.org>

One way I found to get rid of the "package(s) with this id already exist" problem was by doing a "ghc-pkg --force unregister <package>"