{ lib, ... }:
with lib;
{
  config.outputKinds = [
    (
      { hasSystem, ... }:
      optionalAttrs (!hasSystem) {
        options = {
          nixosConfigurations = mkOption {
            type = with types; attrsOf anything;
            description = "Used with `nixos-rebuild switch --flake .#<hostname>`";
          };
        };
        outputs = { config, ... }: {
          nixosConfigurations = config.nixosConfigurations;
        };
      }
    )
  ];
}