anchor.diff:  
   , # Shell code executed after the VM has finished.
     postVM ? ""
  +
  +, # Copy the contents of the Nix store to the root of the image and
  +  # skip further setup. Incompatible with `contents`,
  +  # `installBootLoader` and `configFile`.
  +  onlyNixStore ? false
   
   , name ? "nixos-disk-image"
   
  
positive.code:         tune2fs -T now -c 0 -i 0 $rootDisk
        ''}
      ''
  )
  
negative.code:   fsType ? "ext4"
  
  , # Filesystem label
    label ? if onlyNixStore then "nix-store" else "nixos"
  
  , # The initial NixOS configuration file to be copied to
    # /etc/nixos/configuration.nix.
  