[nix-shell:~/proj/nix/nixpkgs]$ which nix                                                      
/nix/store/cchfc7cdajg5kbx31x6y6bn8ridqw6k1-nix-2.17.0/bin/nix                                 
                                                                                               
[nix-shell:~/proj/nix/nixpkgs]$ uname                                                          
FreeBSD 

yay