$ git clone -n https://gitee.com/opencloudos-stream/libcerf.git /var/lib/mock/dist-oc9-epol-build-79449-53370/root/chroot_tmpdir/scmroot/libcerf
Cloning into '/var/lib/mock/dist-oc9-epol-build-79449-53370/root/chroot_tmpdir/scmroot/libcerf'...
$ git fetch origin master:KOJI_FETCH_HEAD
From https://gitee.com/opencloudos-stream/libcerf
 * [new branch]      master     -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d4b4666 update