$ git clone -n https://src.fedoraproject.org/rpms/ocaml-mdx.git /var/lib/mock/f40-build-2244538-53715/root/chroot_tmpdir/scmroot/ocaml-mdx
Cloning into '/var/lib/mock/f40-build-2244538-53715/root/chroot_tmpdir/scmroot/ocaml-mdx'...
$ git fetch origin cda6b7b02c74c4c76f76bb1598e15af5aaf06e0e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ocaml-mdx
 * [new ref]         cda6b7b02c74c4c76f76bb1598e15af5aaf06e0e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cda6b7b Bump release and rebuild