anchor.diff:  { stdenv, fetchFromGitHub, cmake, python }:
   
   stdenv.mkDerivation rec {
  -  version = "0.6.2";
  +  version = "0.6.3";
     pname = "docopt.cpp";
   
     src = fetchFromGitHub {
       owner = "docopt";
       repo = "docopt.cpp";
       rev = "v${version}";
  -    sha256 = "1rgkc8nsc2zz2lkyai0y68vrd6i6kbq63hm3vdza7ab6ghq0n1dd";
  +    sha256 = "0cz3vv7g5snfbsqcf3q8bmd6kv5qp84gj3avwkn4vl00krw13bl7";
     };
   
     nativeBuildInputs = [ cmake python ];
  
positive.code:     maintainers = with maintainers; [ knedlsepp ];
    };
  }
  
  
negative.code:   cmakeFlags = ["-DWITH_TESTS=ON"];
  
    doCheck = true;
  
    postPatch = ''
      substituteInPlace docopt.pc.in \
        --replace "@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@" \
                  "@CMAKE_INSTALL_LIBDIR@"
    '';
  
    checkPhase = "LD_LIBRARY_PATH=$(pwd) python ./run_tests";
  
  