ocamlnet needs an update for 4.05
The upcoming 4.05 release breaks the build of 4.1.2.
opam-builder report: http://opam.ocamlpro.com/builder/html/ocamlnet/ocamlnet.4.1.2/05c7405b69fdeaa0ad4dcd976ca3d6d4
Error: This variant or record definition does not match that of type Unix.open_flag. The field O_KEEPEXEC is only present in the original definition.
O_KEEPEXEC
was introduced in the Unix library in
https://github.com/ocaml/ocaml/pull/650