TWIN: Enhanced FreeBSD support for nix and nixpkgs is on its way thanks to rhelmot and artemist! As of this week, nix support for sandboxed building with FreeBSD jails is an open pull request, along with a fully fledged stdenv for native use of nix on FreeBSD. Progress is ongoing to support desktop environments and a full FreeBSD-based nixos platform.

Due to a review of the FreeBSD backwards compatibility capabilities, the platform tuple was able to change to drop the major version number. Packages will be built by default for the lowest supported version of FreeBSD (14 at present), but can be built to take advantage of newer features by specifying build parameters.

For more information, check out https://github.com/NixOS/nixpkgs/pull/254801#issuecomment-1937118809