$ git clone -n https://gitee.com/opencloudos-stream/libb64.git /var/lib/mock/dist-oc9-epol-build-82654-57125/root/chroot_tmpdir/scmroot/libb64
Cloning into '/var/lib/mock/dist-oc9-epol-build-82654-57125/root/chroot_tmpdir/scmroot/libb64'...
$ git fetch origin master:KOJI_FETCH_HEAD
From https://gitee.com/opencloudos-stream/libb64
 * [new branch]      master     -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 234e06c package init