repo_path = ex_base_exe_ex.toStdString() + target_name;
    std::cout << "target_name: " << target_name << std::endl;
    std::cout << "repo_path: " << repo_path << std::endl;
    std::cout << "src_name: " << src_name << std::endl;
    std::cout << "remote_url: " << remote_url << std::endl;
    /*
    if (git_mode == GIT_MODE::BRANCH)
    {
        clone_branch();
    }
    else if (git_mode == GIT_MODE::TAG)
    {
        clone_tag();
    }
    */
    git_libgit2_init();
    // create a bare local repository
    git_repository_init(&repo, repo_path.c_str(), false);
    // set remote url
    git_remote_create(&remote, repo, "origin", remote_url.c_str());
    // generate refspec
    // http://git-scm.com/docs/git-rev-parse.html#_specifying_revisions
    std::string refspec; // for git fetch
    std::string revspec; // for git checkout
    /*
    if (branch_name.size())
    {
        refspec = "+refs/heads/" + branch_name + ":refs/remotes/origin/" + branch_name;
        revspec = "refs/remotes/origin/" + branch_name;
    }
    */
    std::string target_name="457140_457141_5898877434354585407";
    if (target_name.size())
    {
        refspec = "+refs/tags/" + target_name + ":refs/tags/" + target_name;
        revspec = "refs/tags/"+target_name;
    }
    // construct fetch_opts and run fetch
    // for libgit:v1.7.0 the GIT_FETCH_OPTIONS_INIT was
    // missing some field, so we must assign then manually.
    char *refspec_addr[] = {refspec.data()};
    git_strarray refspecs{refspec_addr, 1};

    git_fetch_options fetch_opt = GIT_FETCH_OPTIONS_INIT;
    fetch_opt.proxy_opts.type = GIT_PROXY_AUTO;
    fetch_opt.depth = 1;
    fetch_opt.follow_redirects = GIT_REMOTE_REDIRECT_INITIAL;
    fetch_opt.custom_headers = git_strarray{nullptr, 0};
    git_remote_fetch(remote, &refspecs, &fetch_opt, NULL);

    // find revision
    git_object *rev;
    git_revparse_single(&rev, repo, revspec.c_str());

    // git checkout $branch
    // git checkout tags/$tag
    git_checkout_options checkout_opts = GIT_CHECKOUT_OPTIONS_INIT;
    checkout_opts.checkout_strategy = GIT_CHECKOUT_SAFE;
    git_reset(repo, rev, GIT_RESET_HARD, &checkout_opts);

    // finally close
    git_remote_free(remote);
    git_repository_free(repo);