anchor.diff:  
   buildPythonPackage rec {
     pname = "symengine";
  -  version = "0.4.0";
  +  version = "0.6.1";
   
     src = fetchFromGitHub {
       owner = "symengine";
       repo = "symengine.py";
       rev = "v${version}";
  -    sha256 = "07i9rwxphi4zgwc7y6f6qvq73iym2cx4k1bpd7rmd3wkpgrrfxqx";
  +    sha256 = "13fy25qxn4xwzlr2w35v6jhlpd70lv9r6srv4dizc4brj63hnw50";
     };
   
     postConfigure = ''
  
positive.code:     homepage = "https://github.com/symengine/symengine.py";
      license = licenses.mit;
      maintainers = [ maintainers.costrouc ];
      broken = true;
    };
  }
  
negative.code:       --replace "SET(CYTHON_BIN cython" "SET(CYTHON_BIN ${cython}/bin/cython"
    '';
  
    nativeBuildUnputs = [ cmake ];
  
    buildInputs = [ cython ];
  
    checkInputs = [ pytest sympy ];
  
  