$ git clone -n https://gitee.com/mgb01105731/postfix.git /var/lib/mock/dist-an23-build-345512-70116/root/chroot_tmpdir/scmroot/postfix
Cloning into '/var/lib/mock/dist-an23-build-345512-70116/root/chroot_tmpdir/scmroot/postfix'...
$ git fetch origin a23:KOJI_FETCH_HEAD
From https://gitee.com/mgb01105731/postfix
 * [new branch]      a23        -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 96d6b0d update to 3.7.9