anchor.diff:        "--register"
       ];
   
  -    vmFlags = mkFlags [
  +    vmFlags = mkFlags ([
         "--uart1 0x3F8 4"
         "--uartmode1 client /run/virtualbox-log-${name}.sock"
  -    ];
  +    ] ++ (attrs.vmFlags or []));
   
       controllerFlags = mkFlags [
         "--name SATA"
  
positive.code:       $machine->screenshot("gui_manager_started");
        $machine->sendKeys("ret");
        $machine->screenshot("gui_manager_sent_startup");
        waitForStartup_test1;
        $machine->screenshot("gui_started");
        waitForVMBoot_test1;
        $machine->screenshot("gui_booted");
        shutdownVM_test1;
        $machine->sleep(5);
        $machine->screenshot("gui_stopped");
        $machine->sendKeys("ctrl-q");
  
negative.code: import ./make-test.nix ({ pkgs, ... }: with pkgs.lib; let
  
    testVMConfig = vmName: attrs: { config, pkgs, ... }: {
      boot.kernelParams = let
        miniInit = ''
          #!${pkgs.stdenv.shell} -xe
          export PATH="${pkgs.coreutils}/bin:${pkgs.utillinux}/bin"
  
          ${pkgs.linuxPackages.virtualboxGuestAdditions}/sbin/VBoxService
          ${(attrs.vmScript or (const "")) pkgs}
  
          i=0
          while [ ! -e /mnt-root/shutdown ]; do
            sleep 10
            i=$(($i + 10))
            [ $i -le 120 ] || fail
          done
  
          rm -f /mnt-root/boot-done /mnt-root/shutdown
        '';
      in [
        "console=tty0" "console=ttyS0" "ignore_loglevel"
        "boot.trace" "panic=1" "boot.panic_on_fail"
        "init=${pkgs.writeScript "mini-init.sh" miniInit}"
      ];
  
      fileSystems."/" = {
  