anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "plfit";
  -  version = "0.9.3";
  +  version = "0.9.4";
   
     src = fetchFromGitHub {
       owner = "ntamas";
       repo = "plfit";
       rev = version;
  -    hash = "sha256-y4n6AlGtuuUuA+33oF7lGOYuKSqea4GMSJlv9PaSpQ8=";
  +    hash = "sha256-hnmP/56P2anR0S8zQyQqN1lbge5GgK+P8Lx8bRkwSxA=";
     };
  -
  -  patches = [
  -    # https://github.com/ntamas/plfit/pull/41
  -    (fetchpatch {
  -      name = "use-cmake-install-full-dir.patch";
  -      url = "https://github.com/ntamas/plfit/commit/d0e77c80e6e899298240e6be465cf580603f6ee2.patch";
  -      hash = "sha256-wi3qCp6ZQtrKuM7XDA6xCXunCiqsyhnkxmg2eSmxjYM=";
  -    })
  -  ];
   
     nativeBuildInputs = [
       cmake
  
positive.code: { lib
  , stdenv
  , fetchFromGitHub
  , fetchpatch
  , cmake
  , python ? null
  , swig
  
negative.code:   meta = with lib; {
      description = "Fitting power-law distributions to empirical data";
      homepage = "https://github.com/ntamas/plfit";
      changelog = "https://github.com/ntamas/plfit/blob/${src.rev}/CHANGELOG.md";
      license = licenses.gpl2Plus;
      maintainers = with maintainers; [ dotlambda ];
    };
  