Hello, Cygwin’s package “ocaml” is currently at 4.02.3, and “flexdll” is at 0.34. The latest FlexDLL, 0.35, makes it possible to build and use OCaml 4.03.0 and 4.04.0 on Cygwin [1].
I am not sure who is the current maintainer of these packages. I searched the mailing list, and found Damien Doligez apparently submitted OCaml 4.01.0. However, I package releases of OCaml and related packages in little Cygwin mirrors, for use on build bots [2]. If desired, I can adapt the packages to be suitable for public Cygwin, and submit them. I expect to be making the build bot packages for quite a while, so I should be able to also submit to Cygwin on an ongoing basis. Ideally, this would produce OPAM on Cygwin as well. Best, Anton [1]: http://caml.inria.fr/mantis/view.php?id=7268 [2]: https://github.com/aantron/binaries/tree/master/src/build/cygwin