$ git clone -n https://gitee.com/uestc-cheng/libxml2.git /var/lib/mock/dist-an8.8-build-299252-65890/root/chroot_tmpdir/scmroot/libxml2
Cloning into '/var/lib/mock/dist-an8.8-build-299252-65890/root/chroot_tmpdir/scmroot/libxml2'...
$ git reset --hard 6e33a80269d63b8aa0b76a3e1499c684adacf20c
HEAD is now at 6e33a80 update libxml2.spec.