$ git clone -n https://gitee.com/ocs-upgrade/postfix.git /var/lib/mock/dist-ocs23-build-195556-13256/root/chroot_tmpdir/scmroot/postfix
Cloning into '/var/lib/mock/dist-ocs23-build-195556-13256/root/chroot_tmpdir/scmroot/postfix'...
$ git fetch origin master:KOJI_FETCH_HEAD
From https://gitee.com/ocs-upgrade/postfix
 * [new branch]      master     -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a24a457 Upgrade to version 3.9.0