The LTS Haskell 2.0 release is officially out the door. More details are available at: https://www.fpcomplete.com/blog/2015/04/announcing-lts-2 For the tl;dr crowd, run the following inside your project to get a cabal.config with appropriate constraints: wget https://www.stackage.org/lts/cabal.config There are some questions about policy at the end of the post that I'd appreciate feedback on.