let nixpkgs-lock  = (builtins.fromJSON (builtins.readFile ../flake.lock)).nodes.nixpkgs.locked;
in import (fetchTarball {
    url = "https://github.com/nixos/nixpkgs/archive/${nixpkgs-lock.rev}.tar.gz";
    sha256 = nixpkgs-lock.narHash;
})