$ git clone -n https://src.fedoraproject.org/rpms/openttd.git /var/lib/mock/f39-build-1585387-38144/root/chroot_tmpdir/scmroot/openttd
Cloning into '/var/lib/mock/f39-build-1585387-38144/root/chroot_tmpdir/scmroot/openttd'...
$ git fetch origin ff3123737fecf2cf1cc5c27bccfd65e7e9625034:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/openttd
 * [new ref]         ff3123737fecf2cf1cc5c27bccfd65e7e9625034 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ff31237 update to 13.4