anchor.diff:  
   buildPythonPackage rec {
     pname = "pikepdf";
  -  version = "1.1.0";
  +  version = "1.6.2";
     disabled = ! isPy3k;
   
     src = fetchPypi {
       inherit pname version;
  -    sha256 = "14b36r6h3088z2sxp2pqvm171js53hz53mwm1g52iadignjnp0my";
  +    sha256 = "1x1b55znr0j4fib69l2h0xq0qmbf2nbxwbwd4f7y8r4sqi20239z";
     };
   
     buildInputs = [
  
positive.code:   propagatedBuildInputs = [ defusedxml lxml ];
  
    postPatch = ''
      substituteInPlace requirements/test.txt \
         --replace "pytest >= 3.6.0, < 4.1.0" "pytest >= 4.2.1, < 5"
    '';
  
    preBuild = ''
  
negative.code:     maintainers = [ maintainers.kiwi ];
    };
  }
  