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