anchor.diff:  
         # vim undo dir
         mkdir -p $HOME/.vim/undodir
  +
  +      # fasd
  +      eval "$(fasd --init auto)"
       '';
     };
     programs.nix-index.enable = true;
  
positive.code:     "$HOME/.npm/bin"
    ];
  
    environment.variables = { EDITOR = "vim"; };
  
    environment.postBuild = ''
    '';
  
negative.code:       pkgs.jq
        pkgs.fd
        pkgs.rustup
        pkgs.fasd
        my-neovim
      ];
  
  