I really need to get back to https://github.com/NixOS/nixpkgs/pull/82131 so we can build on Linux or BSD, for Linux or BSD, in all 4 combinations. Eventually I want equivalent, NixOS userland, choose kernel on boot.

Nevermind the merits of Linux vs BSD, what we really need is kernel diversity to fight the stagnation of these multi-million-line tarpits of complexity.