$ git clone -n https://gitee.com/opencloudos-stream/desktop-backgrounds.git /var/lib/mock/dist-oc9-epol-build-118097-68870/root/chroot_tmpdir/scmroot/desktop-backgrounds
Cloning into '/var/lib/mock/dist-oc9-epol-build-118097-68870/root/chroot_tmpdir/scmroot/desktop-backgrounds'...
$ git fetch origin master:KOJI_FETCH_HEAD
From https://gitee.com/opencloudos-stream/desktop-backgrounds
 * [new branch]      master     -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a8a9cf2 update