default.nix for my site

{ nixpkgs ? import <nixpkgs> {}, compiler ? "default", doBenchmark ? false }:

let

  inherit (nixpkgs) pkgs;

  haskellPackages = if compiler == "default"
                       then pkgs.haskellPackages
                       else pkgs.haskell.packages.${compiler};

  myHaskellPackages = haskellPackages.override {
    overrides = self: super: {
      hakyll = pkgs.haskell.lib.doJailbreak super.hakyll;
    };
  };

  variant = if doBenchmark then pkgs.haskell.lib.doBenchmark else pkgs.lib.id;

  drv =
    variant (myHaskellPackages.callPackage ./drv.nix {})
      .overrideAttrs (oldAttrs: {
        src = builtins.filterSource (path: type:
           baseNameOf path != "site" && baseNameOf path != "site.nix") ./.;
      });

in
  drv