[Nix-dev] Use GHC 7.10.1 as default Haskell compiler in nixpkgs

[Peter Simons]

Hi Ertugrul,

 > The last time I tried to switch, Nix started to build everything from
 > source, including GHC, even with the options described in the Haskell
 > NG thread.

what architecture do you use? Is it i686-linux by any chance? I'm asking
because Hydra isn't building binaries for that platform at the moment.

You should always get binaries of GHC itself, though. Those are part of
the standard "nixos-unstable" channel.

Best regards,
Peter