anchor.diff:      name = "${pname}";
       exec = "${pname}";
       desktopName = "PyMol Molecular Graphics System";
  -    genericName = "Molecular Modeller";
  +    genericName = "Molecular Modeler";
       comment = description;
       mimeType = "chemical/x-pdb;chemical/x-mdl-molfile;chemical/x-mol2;chemical/seq-aa-fasta;chemical/seq-na-fasta;chemical/x-xyz;chemical/x-mdl-sdf;";
       categories = "Graphics;Education;Science;Chemistry;";
  
positive.code:   name = "pymol-${version}";
    src = fetchurl {
      url = "mirror://sourceforge/project/pymol/pymol/${ver_maj}/pymol-v${version}.tar.bz2";
      sha256 = "0yfj8g5yic9zz6f0bw2n8h6ifvgsn8qvhq84alixsi28wzppn55n";
    };
  
    buildInputs = [ python3Packages.numpy glew freeglut libpng libxml2 tk freetype ];
    NIX_CFLAGS_COMPILE = "-I ${libxml2.dev}/include/libxml2";
  
    installPhase = ''
  
negative.code: { stdenv, fetchurl, makeDesktopItem
  , python3, python3Packages
  , glew, freeglut, libpng, libxml2, tk, freetype, libmsgpack }:
  
  
  with stdenv.lib;
  
  let
    pname = "pymol";
    ver_maj = "2";
    ver_min = "1";
    version = "${ver_maj}.${ver_min}.0";
    description = "A Python-enhanced molecular graphics tool";
  
  