Hello, I'm trying to build Boost.MPI from the 1.44.0 sources; if I uncomment the `#define BOOST_MPI_HOMOGENEOUS` line in `boost/mpi/config.hpp`, then build fails with errors like this one (full compile log attached): ./boost/mpi/detail/binary_buffer_iprimitive.hpp: In member function ‘void boost::mpi::binary_buffer_iprimitive::load(T&) [with T = boost::archive::class_id_optional_type]’: ./boost/archive/detail/iserializer.hpp:107: instantiated from ‘static void boost::archive::load_access::load_primitive(Archive&, T&) [with Archive = boost::mpi::packed_iarchive, T = boost::archive::class_id_optional_type]’ ./boost/archive/detail/iserializer.hpp:356: instantiated from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::load_primitive::invoke(Archive&, T&) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/iserializer.hpp:433: instantiated from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::invoke(Archive&, T&) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/iserializer.hpp:586: instantiated from ‘void boost::archive::load(Archive&, T&) [with Archive = boost::mpi::packed_iarchive, T = boost::archive::class_id_optional_type]’ ./boost/archive/detail/common_iarchive.hpp:66: instantiated from ‘void boost::archive::detail::common_iarchive<Archive>::load_override(T&, int) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/mpi/packed_iarchive.hpp:101: instantiated from ‘void boost::mpi::packed_iarchive::load_override(T&, int, mpl_::false_) [with T = boost::archive::class_id_optional_type]’ ./boost/mpi/packed_iarchive.hpp:118: instantiated from ‘void boost::mpi::packed_iarchive::load_override(T&, int) [with T = boost::archive::class_id_optional_type]’ ./boost/archive/detail/interface_iarchive.hpp:60: instantiated from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/common_iarchive.hpp:54: instantiated from ‘void boost::archive::detail::common_iarchive<Archive>::vload(boost::archive::class_id_optional_type&) [with Archive = boost::mpi::packed_iarchive]’ libs/mpi/src/request.cpp:120: instantiated from here ./boost/mpi/detail/binary_buffer_iprimitive.hpp:87: error: no matching function for call to ‘assertion_failed(mpl_::failed************ boost::serialization::is_bitwise_serializable<boost::archive::class_id_optional_type>::************)’ Boost 1.43.0 compiles just fine with BOOST_MPI_HOMOGENEOUS uncommented. I'm using GCC 4.4.5 on Ubuntu 10.10; OpenMPI 1.4.1 installed from the official Ubuntu package. Is this an issue with the sources? Best regards, Riccardo -- Riccardo Murri, Hadlaubstr. 150, 8006 Zürich (CH)