$ git clone -n https://src.fedoraproject.org/rpms/ocaml-ppx-derivers.git /var/lib/mock/f45-build-20666-572/root/chroot_tmpdir/scmroot/ocaml-ppx-derivers
Cloning into '/var/lib/mock/f45-build-20666-572/root/chroot_tmpdir/scmroot/ocaml-ppx-derivers'...
$ git fetch origin cfb1d189277edd9489e4f1f1c738a70dd350b33c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-ppx-derivers
 * [new ref]         cfb1d189277edd9489e4f1f1c738a70dd350b33c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cfb1d18 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild