anchor.diff:  
   buildPythonPackage rec {
     pname = "fonttools";
  -  version = "4.14.0";
  +  version = "4.18.2";
     disabled = pythonOlder "3.6";
   
     src = fetchFromGitHub {
       owner  = pname;
       repo   = pname;
       rev    = version;
  -    sha256 = "0aiaxjg2v2391gxnhp4nvmgfb3ygm6x7n080s5mnkfjq2bq319in";
  +    sha256 = "0h750gvwpsp7fpmgfwkx93gkaf0m1s698g6r7n4xlaji563nlkiv";
     };
   
     # all dependencies are optional, but
  
positive.code:     matplotlib
      # pens
      reportlab
    ];
  
    preCheck = ''
  
negative.code: , sympy
  , matplotlib
  , reportlab
  , sphinx
  , pytest
  , pytest-randomly
  , glibcLocales
  