$ git clone -n https://src.fedoraproject.org/rpms/ocaml-ppx-deriving-yojson.git /var/lib/mock/f42-build-3346782-45002/root/chroot_tmpdir/scmroot/ocaml-ppx-deriving-yojson
Cloning into '/var/lib/mock/f42-build-3346782-45002/root/chroot_tmpdir/scmroot/ocaml-ppx-deriving-yojson'...
$ git fetch origin 4ea17a5048633270d667124a769b5f0f93969c79:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-ppx-deriving-yojson
 * [new ref]         4ea17a5048633270d667124a769b5f0f93969c79 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4ea17a5 Rebuild for ocaml-ppxlib 0.35.0