anchor.diff:      libwebp
       openexr
       pango
  -    v4l_lib
  +    #v4l_lib
       vala
     ];
   
  
positive.code:     "--without-lua"
      "--without-libspiro"
      "--without-umfpack"
    ];
  
    meta = with stdenv.lib; {
  
negative.code: , libwebp
  , openexr
  , pango
  #, v4l_lib
  , vala
  }:
  
  