$ git clone -n https://gitee.com/src-opencloudos-rpms/postfix.git /var/lib/mock/dist-oc9-la64-build-133912-78838/root/chroot_tmpdir/scmroot/postfix
Cloning into '/var/lib/mock/dist-oc9-la64-build-133912-78838/root/chroot_tmpdir/scmroot/postfix'...
$ git fetch origin oc9:KOJI_FETCH_HEAD
From https://gitee.com/src-opencloudos-rpms/postfix
 * [new branch]      oc9        -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fa1749c import postfix-3.8.5-4.tl4