如何使用libgit2创建一个空提交？

#include <git2.h>

int main() {
    git_libgit2_init();

    git_repository *repo = NULL;
    git_signature *author = NULL;
    git_oid tree_id, commit_id;
    git_treebuilder *builder = NULL;
    git_tree *tree = NULL;
    git_commit *commit = NULL;

    // 初始化仓库
    git_repository_init(&repo, "/path/to/repository", 0);

    // 创建提交者的签名
    git_signature_now(&author, "Your Name", "your.email@example.com");

    // 创建树对象构建器
    git_treebuilder_new(&builder, repo, NULL);

    // 写入空的树对象
    git_treebuilder_write(&tree_id, repo, builder);

    // 创建树对象
    git_tree_lookup(&tree, repo, &tree_id);

    // 创建空的提交对象
    git_commit_create_v(
        &commit_id,
        repo,
        "HEAD",
        author,
        author,
        NULL,
        "Empty commit",
        tree,
        0
    );

    // 查找提交对象
    git_commit_lookup(&commit, repo, &commit_id);

    // 清理资源
    git_commit_free(commit);
    git_tree_free(tree);
    git_treebuilder_free(builder);
    git_signature_free(author);
    git_repository_free(repo);

    git_libgit2_shutdown();
    return 0;
}