$ git clone -n https://gitee.com/src-opencloudos-rpms/libxml2.git /var/lib/mock/dist-oc8-build-251653-84121/root/chroot_tmpdir/scmroot/libxml2
Cloning into '/var/lib/mock/dist-oc8-build-251653-84121/root/chroot_tmpdir/scmroot/libxml2'...
$ git fetch origin 850bd4fa3a74a74b74e1b1bd8b6b9803a2ddb8b7:KOJI_FETCH_HEAD
From https://gitee.com/src-opencloudos-rpms/libxml2
 * [new ref]         850bd4fa3a74a74b74e1b1bd8b6b9803a2ddb8b7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 850bd4f import libxml2-2.9.7-21.tl3.10