$ git clone -n https://gitee.com/opencloudos-stream/libcxx.git /var/lib/mock/dist-ocs23-build-241685-22217/root/chroot_tmpdir/scmroot/libcxx
Cloning into '/var/lib/mock/dist-ocs23-build-241685-22217/root/chroot_tmpdir/scmroot/libcxx'...
$ git fetch origin master:KOJI_FETCH_HEAD
From https://gitee.com/opencloudos-stream/libcxx
 * [new branch]      master     -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fb950bc Rebuilt for loongarch release