$ git clone -n https://src.fedoraproject.org/rpms/ocaml-ppx-optcomp.git /var/lib/mock/f41-build-851950-166154/root/chroot_tmpdir/scmroot/ocaml-ppx-optcomp
Cloning into '/var/lib/mock/f41-build-851950-166154/root/chroot_tmpdir/scmroot/ocaml-ppx-optcomp'...
$ git fetch origin 2f3c6df5614b039196f0fc6c613d01e9368ddf9f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-ppx-optcomp
 * [new ref]         2f3c6df5614b039196f0fc6c613d01e9368ddf9f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2f3c6df Rebuild for ocaml-ppxlib 0.33.0