I'd like to use the new release of ghc (7.10, because of a new feature --
static ptr), and I'm using a single-user
I don't find the wanted new release in the published lists at https://nixos.org/nixos/packages.html; e.g., the latest ghc's revision points to https://github.com/NixOS/nixpkgs/blob/release-14.12/pkgs/development/compilers/ghc/head.nix#L37 (it's pre-7.10; but what's the point in using a pre-release, if a stable 7.10 has been released already since then, 2014-12).
But that's the release branch of nixpkgs (
Looking into other branches, I can find nix expressions for newer ghc:
masterbranch of nixpkgs: https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/compilers/ghc/7.10.1.nix
staging revisions of
ghc/7.10.1.nix are identical.)
How do I install them into my nix environment (perhaps, with re-compilation)?