config.nix

{ pkgs }:

let
  vimrc = import ./vim/vimrc.nix {};

  vimPlugins = import ./vim/vimPlugins.nix { inherit pkgs; };
in

with pkgs; rec {
  allowBroken = true;
  allowUnfree = true;

  build-use-chroot = true;

  vim = {
    gui = "macvim";
  };

  haskellPackageOverrides = with pkgs.haskell.lib; self: super: {
    purescript_0_7_6_1 = dontCheck super.purescript_0_7_6_1;
  };

  packageOverrides = pkgs : rec {
    haskell = pkgs.haskell // {
        ghc763 = pkgs.haskell.packages.ghc763.override {
          overrides = self: pkgs: {
            mkDerivation = args: pkgs.mkDerivation (args // { doHaddock = false; });
          };
        };
      };
    };

    # ... rest of config
  };
}

Error

error: syntax error, unexpected ';', expecting $end, at /Users/bmartin/.nixpkgs/config.nix:154:4