$ git clone -n https://gitee.com/uestc-cheng/libxml2.git /var/lib/mock/dist-an8.8-build-299151-65888/root/chroot_tmpdir/scmroot/libxml2
Cloning into '/var/lib/mock/dist-an8.8-build-299151-65888/root/chroot_tmpdir/scmroot/libxml2'...
$ git fetch origin 247fc0dcc9fc726632a393e29236bbf9a523cc3b:KOJI_FETCH_HEAD
From https://gitee.com/uestc-cheng/libxml2
 * [new ref]         247fc0dcc9fc726632a393e29236bbf9a523cc3b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 247fc0d update libxml2.spec.