anchor.diff:  
       runHook postCheck
     '';
  +
     enableParallelChecking = false;
   
     meta = with lib; {
  
positive.code:   disabledTests = [
      "PythonTestSSLSocket"
    ] ++ lib.optionals stdenv.isDarwin [
      # tests that hang up in the darwin sandbox
      "SecurityTest"
      "SecurityFromBufferTest"
      "python_test"
  
      # tests that fail in the darwin sandbox when trying to use network
      "UnitTests"
      "TInterruptTest"
      "TServerIntegrationTest"
  
negative.code: { lib
  , stdenv
  , fetchurl
  , boost
  , zlib
  , libevent
  , openssl
  , python3
  , cmake
  , pkg-config
  , bison
  , flex
  , static ? stdenv.hostPlatform.isStatic
  }:
  
  