anchor.diff:  { lib, stdenv
   , fetchFromGitHub
  -, fetchpatch
   , zlib
   , expat
   , cmake
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "exiv2";
    version = "0.27.3";
  
    outputs = [ "out" "dev" "doc" "man" ];
  
  
negative.code:     owner = "exiv2";
      repo  = "exiv2";
      rev = "v${version}";
      sha256 = "0m1x79q6i5fw3gr9k0dw0bbl7ym27g9vbmxiamks6yw028xqwc5a";
    };
  
    nativeBuildInputs = [
      cmake
  