let
  sources = import ../sources.nix;
  lib = import (sources.nixpkgs + "/lib");
in
  lib.composeManyExtensions [
    (final: _: {
      inherit (final.callPackage sources.agenix {}) agenix;

      disko =
        final.callPackage (sources.disko + "/package.nix")
        {diskoVersion = sources.disko.version;};
    })

    (_: prev: {
      nur = import sources.nur {
        nurpkgs = prev;
        pkgs = prev;
      };
    })

    ((import sources.wired-notify).overlays.default)
  ]