[Nix-dev] How to set a specific GHC version?

[Peter Simons]

Hi Hilco,

 > 1) GHC 7.6.3 fails to compile;

GHC 7.6.3 compiles just fine on hydra.nixos.org. Could you please share
the error message you get along with some details about which version of
Nixpkgs use and on what platform?

 > 2) Now I'm not using haskellngPackages. And we're supposed to migrate
 > to that, right?

The name haskellngPackages is obsolete since April 19th. If you're
following the unstable channel, then haskellPackages *is* Haskell NG:

  https://github.com/NixOS/nixpkgs/blob/c0c82ea2ebbcf0632260a931cf832cac1c8a014e/pkgs/top-level/all-packages.nix#L14429-14430

As of now, the pre-NG Haskell infrastructure exists only in release-14.x
branches.

Best regards,
Peter