anchor.diff:        "-DgRPC_SSL_PROVIDER=package"
         "-DgRPC_PROTOBUF_PROVIDER=package"
         "-DgRPC_GFLAGS_PROVIDER=package"
  -      "-DgRPC_ABSL_PROVIDER=package"
         "-DBUILD_SHARED_LIBS=ON"
         "-DCMAKE_SKIP_BUILD_RPATH=OFF"
       ];
  
positive.code:   ];
  
    nativeBuildInputs = [ cmake pkg-config ];
    buildInputs = [ zlib c-ares c-ares.cmake-config openssl protobuf gflags abseil-cpp ]
      ++ lib.optionals stdenv.isLinux [ libnsl ];
  
    cmakeFlags =
  
negative.code: { lib, stdenv, fetchFromGitHub, fetchpatch, cmake, zlib, c-ares, pkg-config, openssl, protobuf
  , gflags, libnsl
  }:
  
  stdenv.mkDerivation rec {
    version = "1.35.0"; # N.B: if you change this, change pythonPackages.grpcio-tools to a matching version too
    pname = "grpc";
    src = fetchFromGitHub {
      owner = "grpc";
      repo = "grpc";
      rev = "v${version}";
      sha256 = "0vxgp3kqxsglavzs91ybpkkh7aaywxcryacp5z3z6dpsgmw0mscd";
      fetchSubmodules = true;
    };
    patches = [
  