$ git clone -n https://src.fedoraproject.org/rpms/ocaml-jane-street-headers.git /var/lib/mock/f45-build-20545-571/root/chroot_tmpdir/scmroot/ocaml-jane-street-headers
Cloning into '/var/lib/mock/f45-build-20545-571/root/chroot_tmpdir/scmroot/ocaml-jane-street-headers'...
$ git fetch origin 5ae678436e95a4a76905d074a15712744fd302e0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-jane-street-headers
 * [new ref]         5ae678436e95a4a76905d074a15712744fd302e0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5ae6784 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild