anchor.diff:      };
     };
   
  +
     uncertainties = buildPythonPackage rec {
       name = "uncertainties-2.4.6.1";
   
  
positive.code:       homepage = "http://pythonhosted.org/uncertainties/";
        description = "Transparent calculations with uncertainties on the quantities involved (aka error propagation)";
        license = licenses.bsd3;
      };
    };
  
  
negative.code:     };
    };
  
  
  }); in pythonPackages
  