+ MPI_Group group = new simgrid::smpi::Group(size);
+ comm_world = new simgrid::smpi::Comm(group, nullptr, 0, -1);
+ // FIXME : using MPI_Attr_put with MPI_UNIVERSE_SIZE is forbidden and we make it a no-op (which triggers a warning
+ // as MPI_ERR_ARG is returned). Directly calling Comm::attr_put breaks for now, as MPI_UNIVERSE_SIZE,is <0
+ // instance.comm_world->attr_put<simgrid::smpi::Comm>(MPI_UNIVERSE_SIZE, reinterpret_cast<void*>(instance.size));