anchor.diff:      lz4
       xz
       zlib
  -    jemalloc
       libunwind
  -    fmt
  +    fmt_8
  +    zstd
     ];
   
  +  NIX_CFLAGS_COMPILE = [ "-DFOLLY_MOBILE=${if follyMobile then "1" else "0"}" ];
     cmakeFlags = [ "-DBUILD_SHARED_LIBS=ON" ];
   
     meta = with lib; {
  
positive.code: { lib, stdenv
  , fetchFromGitHub
  , cmake
  , boost
  , libevent
  , double-conversion
  , glog
  , gflags
  , libiberty
  , lz4
  , xz
  , zlib
  , jemalloc
  , openssl
  , pkg-config
  , libunwind
  , fmt
  }:
  
  stdenv.mkDerivation (rec {
    pname = "folly";
    version = "2021.10.25.00";
  
    src = fetchFromGitHub {
      owner = "facebook";
      repo = "folly";
      rev = "v${version}";
      sha256 = "sha256-+di8Dzt5NRbqIydBR4sB6bUbQrZZ8URUosdP2JGQMec=";
    };
  
    nativeBuildInputs = [
  
negative.code:     homepage = "https://github.com/facebook/folly";
      license = licenses.asl20;
      # 32bit is not supported: https://github.com/facebook/folly/issues/103
      platforms = [ "x86_64-linux" "x86_64-darwin" "aarch64-darwin" ];
      maintainers = with maintainers; [ abbradar pierreis ];
    };
  }
  