You can. For example: https://github.com/NixOS/nixpkgs/blob/fde16189feaa6eaa81bcf9fe54988d92145e9d41/pkgs/applications/audio/reaper/default.nix#L31 https://gith

You can. For example: https://github.com/NixOS/nixpkgs/blob/fde16189feaa6eaa81bcf9fe54988d92145e9d41/pkgs/applications/audio/reaper/default.nix#L31 https://github.com/NixOS/nixpkgs/blob/fde16189feaa6eaa81bcf9... If something gets built it likely means the sources available in some way, just not opensource. There may be many reasons they're preferred over a binary.