anchor.diff:        flask-openid = self.callPackage ./flask-openid.nix {};
         python-openid = self.callPackage ./python-openid.nix {};
         sagenb = self.callPackage ./sagenb.nix {
  -        mathjax = nodePackages_8_x.mathjax;
  +        mathjax = nodePackages.mathjax;
         };
   
         # Package with a cyclic dependency with sage
  
positive.code:     inherit pari_data ecl;
      inherit singular;
      cysignals = python.pkgs.cysignals;
      three = nodePackages_8_x.three;
      mathjax = nodePackages_8_x.mathjax;
    };
  
    # The shell file that gets sourced on every sage start. Will also source
  
negative.code:     inherit sage-env;
      inherit pynac singular;
      pkg-config = pkgs.pkgconfig; # not to confuse with pythonPackages.pkgconfig
      three = nodePackages.three;
    };
  
    # Doesn't actually build anything, just runs sages testsuite. This is a
  