Checkout local commit with libgit2

I'm trying to implement a simple checkout operation between 2 commit. The code executes without errors.

int checkout2() {
git_repository_free(repo);

git_repository_open(&this->repo, this->dir);

git_commit* commit = NULL;

git_tree* tree;
check_lg2(git_commit_tree(&tree, commit), "Get tree", NULL);

const char* target_ref = "commit hash";

git_checkout_options opts = GIT_CHECKOUT_OPTIONS_INIT;

/*checkout from HEAD*/
int error = git_checkout_head(repo, &opts);

/*Checkout from the index*/
error = git_checkout_index(repo, NULL, &opts);

/*Checkout a different tree*/
git_object* treeish = NULL;

error = git_revparse_single(&treeish, repo, target_ref);
error = git_checkout_tree(repo, treeish, &opts);

return 0;

}

However, the commit does not change. I've checked the example in libgit2 (checkout.cpp) but there is a git_remote_list().

I want to checkout only between local commit.

What am I doing wrong?

I want to do something like git checkout hash_commit

int checkout() {
git_repository_free(repo);

git_repository_open(&this->repo, this->dir);

git_commit* commit = NULL;

git_checkout_options checkout_opts = GIT_CHECKOUT_OPTIONS_INIT;
git_reference* ref = NULL, * branch = NULL;
git_commit* target_commit = NULL;
int err;

const char* target_ref;

target_ref = "commit hash";

/** Setup our checkout options from the parsed options */
checkout_opts.checkout_strategy = GIT_CHECKOUT_SAFE;
checkout_opts.checkout_strategy = GIT_CHECKOUT_FORCE;

git_annotated_commit* target;

resolve_refish(&target, repo, target_ref);

/** Grab the commit we're interested to move to */
err = git_commit_lookup(&target_commit, repo, git_annotated_commit_id(target));
if (err != 0) {
    fprintf(stderr, "failed to lookup commit: %s\n", git_error_last()->message);
    return 0;
}

/**
 * Perform the checkout so the workdir corresponds to what target_commit
 * contains.
 *
 * Note that it's okay to pass a git_commit here, because it will be
 * peeled to a tree.
 */
err = git_checkout_tree(repo, (const git_object*)target_commit, &checkout_opts);
if (err != 0) {
    fprintf(stderr, "failed to checkout tree: %s\n", git_error_last()->message);
    return 0;
}

/**
 * Now that the checkout has completed, we have to update HEAD.
 *
 * Depending on the "origin" of target (ie. it's an OID or a branch name),
 * we might need to detach HEAD.
 */
if (git_annotated_commit_ref(target)) {
    const char* target_head;

    if ((err = git_reference_lookup(&ref, repo, git_annotated_commit_ref(target))) < 0) {
    
        return 0;
    }

    if (git_reference_is_remote(ref)) {
        if ((err = git_branch_create_from_annotated(&branch, repo, target_ref, target, 0)) < 0) {

            return 0;
        }
        target_head = git_reference_name(branch);
    }
    else {
        target_head = git_annotated_commit_ref(target);
    }

    err = git_repository_set_head(repo, target_head);
}
else {
    err = git_repository_set_head_detached_from_annotated(repo, target);
}

return 0;

}