That makes sense. For some reasons I was still using the community version of these 2 packages unaware about the "haskell-" prefixed variants.  I actually ended up building them both with `haskell-stack` (which I guess is an alternative solution). Thanks for your quick input. On Thursday, March 10, 2016 10:10 PM, Leif Warner wrote: The "xmonad" and "xmonad-contrib" are from [community]. Are you using [arch-core]? If so, you'd want to use the "haskell-" prefixed variants: "haskell-xmonad" and "haskell-xmonad-contrib". On Thu, Mar 10, 2016 at 10:08 AM, Pierre Radermecker wrote: The recent update seems to have broken my box. After cleaning up everything (removing ghc), installing  xmonad and xmonad-contrib will force downgrading some packages (such as haskell-x11). Then trying to install `haskell-stack` would fail. Is this a known problem ? Cheers, _______________________________________________ arch-haskell mailing list arch-haskell@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/arch-haskell