$ git clone -n https://gitee.com/mgb01105731/postfix.git /var/lib/mock/dist-an23-build-345525-70116/root/chroot_tmpdir/scmroot/postfix
Cloning into '/var/lib/mock/dist-an23-build-345525-70116/root/chroot_tmpdir/scmroot/postfix'...
$ git fetch origin 8fbe868e0774efcfd18b91642eb14bddf6d7e01d:KOJI_FETCH_HEAD
From https://gitee.com/mgb01105731/postfix
 * [new ref]         8fbe868e0774efcfd18b91642eb14bddf6d7e01d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8fbe868 update to 3.7.9