$ git clone -n https://gitee.com/fundawang/libgit2.git /var/lib/mock/dist-an23-build-286401-64832/root/chroot_tmpdir/scmroot/libgit2
Cloning into '/var/lib/mock/dist-an23-build-286401-64832/root/chroot_tmpdir/scmroot/libgit2'...
$ git fetch origin ff4a7001317e39621a3eeff022d1b9e909bb98a6:KOJI_FETCH_HEAD
From https://gitee.com/fundawang/libgit2
 * [new ref]         ff4a7001317e39621a3eeff022d1b9e909bb98a6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ff4a700 1.6.4