$ git clone -n https://src.fedoraproject.org/rpms/ocaml-ppx-optcomp.git /var/lib/mock/f42-build-3357704-45030/root/chroot_tmpdir/scmroot/ocaml-ppx-optcomp
Cloning into '/var/lib/mock/f42-build-3357704-45030/root/chroot_tmpdir/scmroot/ocaml-ppx-optcomp'...
$ git fetch origin 1be77d4d99f3b4426309bf6a4544c3216bea4a54:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-ppx-optcomp
 * [new ref]         1be77d4d99f3b4426309bf6a4544c3216bea4a54 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1be77d4 Rebuild for ocaml-ppxlib 0.35.0