mkFlag()
            .longName("help")
            .description("show usage information")
            .handler([&]() {

        addFlag({
            .longName = "help",
            .description = "show usage information",
            .handler = {[&]() {

            });

            }}
        });

        mkFlag()
            .longName("gc-roots-dir")
            .description("garbage collector roots directory")
            .labels({"path"})
            .dest(&gcRootsDir);

        addFlag({
            .longName = "gc-roots-dir",
            .description = "garbage collector roots directory",
            .labels = {"path"},
            .handler = {&gcRootsDir}
        });

        mkFlag()
            .longName("dry-run")
            .description("don't create store derivations")
            .set(&dryRun, true);

        addFlag({
            .longName = "dry-run",
            .description = "don't create store derivations",
            .handler = {&dryRun, true}
        });

        mkFlag()
            .longName("flake")
            .description("build a flake")
            .set(&flake, true);

        addFlag({
            .longName = "flake",
            .description = "build a flake",
            .handler = {&flake, true}
        });