anchor.diff:  
       sub closeWin {
         Machine::retry sub {
  -        $machine->execute("${xdo "close-window" ''
  +        $machine->execute(ru "${xdo "close-window" ''
             search --onlyvisible --name "new tab"
             windowfocus --sync
             windowactivate --sync
           ''}");
  -        $machine->execute("${xdo "close-window" ''
  +        $machine->execute(ru "${xdo "close-window" ''
             key Ctrl+w
           ''}");
           for (1..20) {
  -          my ($status, $out) = $machine->execute("${xdo "wait-for-close" ''
  +          my ($status, $out) = $machine->execute(ru "${xdo "wait-for-close" ''
               search --onlyvisible --name "new tab"
             ''}");
             return 1 if $status != 0;
  
positive.code:       xdoScript = pkgs.writeText "${name}.xdo" text;
      in "${pkgs.xdotool}/bin/xdotool '${xdoScript}'";
    in ''
      sub createNewWin {
        $machine->nest("creating a new Chromium window", sub {
          $machine->execute("${xdo "new-window" ''
            search --onlyvisible --name "startup done"
            windowfocus --sync
            windowactivate --sync
          ''}");
          $machine->execute("${xdo "new-window" ''
            key Ctrl+n
          ''}");
        });
  
negative.code: 
        $machine->screenshot("sandbox_info");
  
        $machine->succeed(ru "${xdo "submit-url" ''
          search --sync --onlyvisible --name "sandbox status"
          windowfocus --sync
        ''}");
        $machine->succeed(ru "${xdo "submit-url" ''
          key --delay 1000 Ctrl+a Ctrl+c
        ''}");
  
        my $clipboard = $machine->succeed(ru "${pkgs.xclip}/bin/xclip -o");
        die "sandbox not working properly: $clipboard"
        unless $clipboard =~ /namespace sandbox.*yes/mi
            && $clipboard =~ /pid namespaces.*yes/mi
  