anchor.diff:    ];
   
     nativeBuildInputs = [ xxd ];
  -  buildInputs = [ readline openssl ];
  +  buildInputs = [ readline openssl libffi ];
  +  enableParallelBuilding = true;
   
     installPhase = ''
       install -Dm755 -t $out/bin tpl
  
positive.code: 
    doCheck = true;
    preCheck = ''
      # Disable test 81 due to floating point error
      rm tests/issues/test081.expected tests/issues/test081.pl
    '';
  
    meta = with lib; {
      description = "A compact, efficient Prolog interpreter written in ANSI C";
      homepage = "https://github.com/infradig/trealla";
      license = licenses.mit;
      maintainers = with maintainers; [ siraben ];
      mainProgram = "tpl";
  
negative.code: { lib, stdenv, fetchFromGitHub, readline, openssl, libffi, withThread ? true, withSSL ? true, xxd }:
  
  stdenv.mkDerivation rec {
    pname = "trealla";
    version = "2.2.6";
  
    src = fetchFromGitHub {
      owner = "trealla-prolog";
      repo = "trealla";
      rev = "v${version}";
      sha256 = "sha256-DxlexijQPcNxlPjo/oIvsN//8nZ0injXFHc2t3n4yjg=";
    };
  
    postPatch = ''
  