{
  pkgsNix ? (import ../nix/pkgs.nix),
  buildSystem ? builtins.currentSystem,
}: let
  pkgs = pkgsNix.default { inherit buildSystem; };
  busiless = pkgs.callPackage ../nix/busiless.nix {};
in
  pkgs.mkShell {
    buildInputs = [ busiless ];
  }