anchor.diff:  
       vmFlags = mkFlags [
         "--uart1 0x3F8 4"
  -      "--uartmode1 client /run/virtualbox-log.sock"
  +      "--uartmode1 client /run/virtualbox-log-${name}.sock"
       ];
   
       controllerFlags = mkFlags [
  
positive.code: 
      cat > /mnt/grub/grub.cfg <<GRUB
      set root=hd0,1
      linux /linux ${pkgs.lib.concatStringsSep " " cfg.boot.kernelParams}
      initrd /initrd
      boot
      GRUB
      umount /mnt
    '');
  
  in {
    name = "virtualbox";
  
    machine = { pkgs, ... }: {
      imports = [ ./common/user-account.nix ./common/x11.nix ];
      services.virtualboxHost.enable = true;
  
      systemd.sockets.vboxtestlog = {
        description = "VirtualBox Test Machine Log Socket";
        wantedBy = [ "sockets.target" ];
        before = [ "multi-user.target" ];
        socketConfig.ListenStream = "/run/virtualbox-log.sock";
        socketConfig.Accept = true;
      };
  
      systemd.services."vboxtestlog@" = {
        description = "VirtualBox Test Machine Log";
        serviceConfig.StandardInput = "socket";
        serviceConfig.StandardOutput = "syslog";
        serviceConfig.SyslogIdentifier = "testvm";
        serviceConfig.ExecStart = "${pkgs.coreutils}/bin/cat";
      };
    };
  
    testScript = let
      mkFlags = pkgs.lib.concatStringsSep " ";
  
      createFlags = mkFlags [
        "--ostype Linux26"
  
negative.code: import ./make-test.nix ({ pkgs, ... }: with pkgs.lib; let
  
    testVMConfig = { config, pkgs, ... }: {
      boot.kernelParams = [
  