The -o and -c options of ocamlc/ocamlopt were modified to be stricter in 4.04.0. da56cf6dfd The changes in Examples/Makefile.in are compatible with earlier OCaml versions (at least back to 3.12.0).
da56cf6dfd
It is based on the Python class example. The Makefile is based on the Makefile used in the OCaml shapes example.