$ git clone -n https://src.fedoraproject.org/rpms/ocaml-ppx-base.git /var/lib/mock/f41-build-838579-159715/root/chroot_tmpdir/scmroot/ocaml-ppx-base
Cloning into '/var/lib/mock/f41-build-838579-159715/root/chroot_tmpdir/scmroot/ocaml-ppx-base'...
$ git fetch origin 816e5315362bd7ddf294f2ad5ec7a14831035818:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-ppx-base
 * [new ref]         816e5315362bd7ddf294f2ad5ec7a14831035818 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 816e531 Rebuild for ocaml-ppxlib 0.33.0