Current trunk does not compile for me as follows: ./boost/graph/distributed/detail/mpi_process_group.ipp: In function ‘int boost::graph::distributed::receive(const boost::graph::distributed::mpi_process_group&, int, int, T&)’: ./boost/graph/distributed/detail/mpi_process_group.ipp:722: error: ‘stderr’ was not declared in this scope ./boost/graph/distributed/detail/mpi_process_group.ipp:724: error: there are no arguments to ‘fprintf’ that depend on a template parameter, so a declaration of ‘fprintf’ must be available ./boost/graph/distributed/detail/mpi_process_group.ipp:724: note: (if you use ‘-fpermissive’, G++ will accept your code, but allowing the use of an undeclared name is deprecated) ./boost/graph/distributed/detail/mpi_process_group.ipp: In function ‘typename boost::enable_if<boost::mpi::is_mpi_datatype<T>, std::pair<int, unsigned int> >::type boost::graph::distributed::receive(const boost::graph::distributed::mpi_process_group&, int, int, T*, size_t)’: OK to apply the attached? - Volodya