$ git clone -n https://src.fedoraproject.org/rpms/ocaml-ppx-derivers.git /var/lib/mock/f40-build-2013481-45891/root/chroot_tmpdir/scmroot/ocaml-ppx-derivers
Cloning into '/var/lib/mock/f40-build-2013481-45891/root/chroot_tmpdir/scmroot/ocaml-ppx-derivers'...
$ git fetch origin 078fb312d87cb7820b6a182a8e575f5a9342605d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-ppx-derivers
 * [new ref]         078fb312d87cb7820b6a182a8e575f5a9342605d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 078fb31 OCaml 5.1.1 rebuild for Fedora 40