anchor.diff:          ../../nixos/modules/testing/test-instrumentation.nix
           { boot.initrd.kernelModules = [ "virtio" "virtio_blk" "virtio_pci" "virtio_ring" ];
             ec2.hvm = true;
  +
  +          # Hack to make the partition resizing work in QEMU.
  +          boot.initrd.postDeviceCommands = mkBefore
  +            ''
  +              ln -s vda /dev/xvda
  +              ln -s vda1 /dev/xvda1
  +            '';
           }
         ];
       }).config.system.build.amazonImage;
  
positive.code:       $machine->succeed("echo localhost,127.0.0.1 ${snakeOilPublicKey} > ~/.ssh/known_hosts");
        $machine->succeed("ssh -o BatchMode=yes localhost exit");
  
        $machine->shutdown;
      '';
    };
  
  
negative.code:           mkdir $imageDir, 0700;
            my $diskImage = "$imageDir/machine.qcow2";
            system("qemu-img create -f qcow2 -o backing_file=${image}/nixos.img $diskImage") == 0 or die;
            system("qemu-img resize $diskImage 10G") == 0 or die;
  
            # Note: we use net=169.0.0.0/8 rather than
            # net=169.254.0.0/16 to prevent dhcpcd from getting horribly
  