self: super:

let
  brittanyPkgs = import (super.fetchFromGitHub {
    owner = "NixOS";
    repo = "nixpkgs";
    rev = "1cfa5edf5a138136cf2cb04156957d8b315074e1";
    sha256 = "0y9bnd6csswkd0yj4d7ydqwyhadmza6lvwii6pgzqv7bnl1d2zbz";
  }) { config.allowBroken = true; };
in
{
  haskellPackages = super.haskellPackages.override {
    overrides = hSelf: hSuper: {
      brittany = brittanyPkgs.haskellPackages.brittany;
    };
  };
}