anchor.diff:    outputs = [ "out" "dev" ];
   
     doCheck = true;
  +  enableParallelBuilding = true;
   
     meta = with lib; {
       homepage = "https://github.com/ngtcp2/nghttp3";
       description = "nghttp3 is an implementation of HTTP/3 mapping over QUIC and QPACK in C.";
       license = licenses.mit;
  -    platforms = platforms.linux;
  +    platforms = platforms.unix;
       maintainers = with maintainers; [ izorkin ];
     };
   }
  
positive.code: { lib, stdenv, fetchFromGitHub
  , autoreconfHook, pkg-config
  , cunit, file
  }:
  
  stdenv.mkDerivation rec {
  
negative.code:     sha256 = "sha256-pV1xdQa5RBz17jDINC2uN1Q+jpa2edDwqTqf8D5VU3E=";
    };
  
    nativeBuildInputs = [ autoreconfHook pkg-config file ];
    checkInputs = [ cunit ncurses ];
  
    preConfigure = ''
      substituteInPlace ./configure --replace /usr/bin/file ${file}/bin/file
  