{ haskellPackages ? (import <nixpkgs> {}).haskellPackages }:

let
    nixpkgs = import <nixpkgs> {};
in

(haskellPackages.buildLocalCabal ./. "hoobuddy").override (old:{
  cabal = old.cabal.override {
    # self is the final package
    # super is the package we are modifying
    extension = self: super: {
      buildDepends = [
        haskellPackages.cabalInstall
        haskellPackages.ghcMod
        haskellPackages.ghcid
      ] ++ super.buildDepends; # Add the build depends of the package
    };

    # I think this probably should be merged with old.extension, but I haven't yet seen
    # this done anywere and it shouldn't matter with standard usage.
  };
})