run_child
run_child(helper_default_path, path);
run_child(helper_custom_basename, path);
run_child(helper_custom_path, "./var/run/my-pidfile.pid");
run_child(helper_change_basenames, NULL);
run_child(helper_change_paths, NULL);
run_child(helper_mix, NULL);
run_child(abs_cc, &args, cpp.outfile, cpp.output_fd);
run_child(abs_lint1, &args, out_fname, -1);
run_child(abs_lint2, &args, lint2.output_library, -1);