Interesting that they pin Pyre’s Unixisms on “OCaml’s ecosystem” when they really mean just Jane Street’s Core and their own code, even their own Python code.
Not that I disagree with the decision, I’m glad you brought up the topic. OCaml the language is quite good, but opam switches are too slow and brittle to setup, specially on Windows, and it lacks any reasonable support for cross-compilation. Plus, I don’t really like opam as a tool, or the way the repository is managed.
Last time I tried to install OCaml on Windows I simply gave up after an hour of waiting, so I’ve sadly started to consider Rust or even Go (shudders) to migrate a couple of personal projects to.