{ inputs ? import ../../inputs.nix {}}:

let
  nixos-cosmic = inputs.cosmic-modules;
  cosmicPkgsMainDir = builtins.readDir "${nixos-cosmic}/pkgs";
  cosmicPkgsDirs = builtins.filter (v: cosmicPkgsMainDir."${v}" == "directory") (builtins.attrNames cosmicPkgsMainDir);

  # FIXME: use unstable nixpkgs when rust 1.80 will be available in unstable
  stagingNixpkgsSrc = builtins.fetchTarball {
    name = "nixpkgs";
    url = "https://github.com/NixOS/nixpkgs/archive/b79cec4237cd0f655562890bf927466c68b48d68.tar.gz";
    sha256 = "1mswisq9iwffg2d6rfxvr27mvi4w853d9rn222s2g76445d0iqh8";
  };
  cosmicOverlay = self: super: builtins.listToAttrs (
    builtins.map (v: {name = v; value = self.callPackage "${nixos-cosmic}/pkgs/${v}/package.nix" {};}) cosmicPkgsDirs
  );
in

self: super:

let
stagingNixpkgs = import stagingNixpkgsSrc {
    localSystem = self.stdenv.buildPlatform;
    config = self.config;
    overlays = [ cosmicOverlay ];
  } // (if self.stdenv.buildPlatform == self.stdenv.hostPlatform then {} else {
    crossSystem = self.stdenv.hostPlatform;
  });
in

builtins.listToAttrs (
  builtins.map (v: {name = v; value = stagingNixpkgs.${v};}) cosmicPkgsDirs
)