message: examples: Fix helloSstWriter to avoid MPI constructor in serial build
diff: @@ -30,7 +30,6 @@ int main(int argc, char *argv[])
  #else
  rank = 0;
  size = 1;
  -#define MPI_COMM_WORLD 0
  #endif
  std::vector<float> myFloats = {
  @@ -42,7 +41,11 @@ int main(int argc, char *argv[])
  try
  {
  +#if ADIOS2_USE_MPI
  adios2::ADIOS adios(MPI_COMM_WORLD);
  +#else
  + adios2::ADIOS adios;
  +#endif
  adios2::IO sstIO = adios.DeclareIO("myIO");
  sstIO.SetEngine("Sst");
  