$ git clone -n https://gitee.com/uestc-cheng/libxml2.git /var/lib/mock/dist-an8.8-build-299449-65890/root/chroot_tmpdir/scmroot/libxml2
Cloning into '/var/lib/mock/dist-an8.8-build-299449-65890/root/chroot_tmpdir/scmroot/libxml2'...
$ git fetch origin 6e45bab877b93867caf919e45d2c0fcb1ec7ef26:KOJI_FETCH_HEAD
From https://gitee.com/uestc-cheng/libxml2
 * [new ref]         6e45bab877b93867caf919e45d2c0fcb1ec7ef26 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6e45bab update libxml2.spec.