$ git clone -n https://src.fedoraproject.org/rpms/ocaml-zarith.git /var/lib/mock/f45-build-20778-573/root/chroot_tmpdir/scmroot/ocaml-zarith
Cloning into '/var/lib/mock/f45-build-20778-573/root/chroot_tmpdir/scmroot/ocaml-zarith'...
$ git fetch origin d5f287ea64fceb7cf4c98453103cc82d1e67f8e0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-zarith
 * [new ref]         d5f287ea64fceb7cf4c98453103cc82d1e67f8e0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d5f287e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild