args@{ version ? "19.03", ... }:
with builtins;
let
  pin = fromJSON (readFile (./nixpkgs- + version + ".json"));

  # Prepend the default overlay to args.overlays
  overlays = [ (import ../pkgs) ] ++ (args . overlays or []);
  nixpkgsArgs = (removeAttrs args ["version"]) // {overlays = overlays;};

  pkgs = import (fetchTarball { inherit (pin) url sha256; }) nixpkgsArgs;

  # Anything can be set in passthru.
  # These variables are used in common/default.nix to generate the NixOS version suffix.
  passthru = {
    inherit nixRev gitBranch gitRev;
  };

in
  pkgs