$ git clone -n https://gitee.com/mgb01105731/libb2.git /var/lib/mock/dist-an23-build-353645-71027/root/chroot_tmpdir/scmroot/libb2
Cloning into '/var/lib/mock/dist-an23-build-353645-71027/root/chroot_tmpdir/scmroot/libb2'...
$ git fetch origin a23:KOJI_FETCH_HEAD
From https://gitee.com/mgb01105731/libb2
 * [new branch]      a23        -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e8123e1 init package from upstream