anchor.diff:      nlopt
       lp_solve
       colpack
  -  ] ++ lib.optionals pythonSupport (with python2Packages; [ python numpy ])
  +  ] ++ lib.optionals pythonSupport (with python3Packages; [ python numpy ])
       ++ lib.optional opencvSupport opencv;
   
     cmakeFlags = let
  
positive.code: , lp_solve
  , colpack
    # extra support
  , pythonSupport ? true
  , opencvSupport ? false
  , opencv ? null
  , withSvmLight ? false
  }:
  
  assert pythonSupport -> python2Packages != null;
  assert opencvSupport -> opencv != null;
  
  assert (!blas.isILP64) && (!lapack.isILP64);
  
negative.code:   ] ++ lib.optional (!withSvmLight) ./svmlight-scrubber.patch;
  
    nativeBuildInputs = [ cmake swig ctags ]
      ++ (with python3Packages; [ python jinja2 ply ]);
  
    buildInputs = [
      eigen
  