anchor.diff:  
               environment.systemPackages = [
                 # To avoid clashing with xfce4-terminal
  -              pkgs.alacritty 
  +              pkgs.alacritty
               ];
   
   
  -            services.xserver = 
  +            services.xserver =
               {
                 enable = true;
   
  
positive.code: import ../make-test-python.nix ( 
    {
      pkgs, ...
    }: 
      # copy_from_host works only for store paths
      rec {
          name = "fcitx";
          machine = 
          { 
            pkgs, 
            ... 
          }: 
            {
              virtualisation.memorySize = 1024;
  
  
negative.code:           }
          ;
  
          testScript = { nodes, ... }:
          let
              user = nodes.machine.config.users.users.alice;
              userName      = user.name;
              userHome      = user.home;
              xauth         = "${userHome}/.Xauthority";
              fcitx_confdir = "${userHome}/.config/fcitx";
          in
          ''
              # We need config files before login session
              # So copy first thing
  