anchor.diff:  { stdenv, ensureNewerSourcesHook, autoconf, automake, makeWrapper, pkgconfig
   , libtool, which, git
  -, boost, python, pythonPackages, libxml2, zlib
  +, boost, python2Packages, libxml2, zlib
   
   # Optional Dependencies
   , snappy ? null, leveldb ? null, yasm ? null, fcgi ? null, expat ? null
  
positive.code:   };
  
    wrapArgs = "--set PYTHONPATH \"$(toPythonPath $lib)\""
      + " --prefix PYTHONPATH : \"$(toPythonPath ${pythonPackages.flask})\""
      + " --set PATH \"$out/bin\"";
  in
  stdenv.mkDerivation {
  
negative.code:     (ensureNewerSourcesHook { year = "1980"; })
    ]
      ++ optionals (versionAtLeast version "9.0.2") [
        python2Packages.setuptools python2Packages.argparse
      ];
    buildInputs = buildInputs ++ cryptoLibsMap.${cryptoStr} ++ [
      boost python libxml2 optYasm optLibatomic_ops optLibs3 malloc python2Packages.flask zlib
    ] ++ optionals (versionAtLeast version "9.0.0") [
      python2Packages.sphinx # Used for docs
    ] ++ optionals stdenv.isLinux [
      linuxHeaders libuuid udev keyutils optLibaio optLibxfs optZfs
    ] ++ optionals hasServer [
  