id summary reporter owner description type status milestone component version severity resolution keywords cc 9208 MPI failure on big endian machines Steve Nolen Matthias Troyer On big endian machines (i.e. LLNL's Sequoia) the boost MPI implementation is broken. When a class's version is written to a packed_oarchive, the value (an unsigned int, uint32) is written as a 1-byte integer. The process sort of works on little endian machines where the least significant byte is being copied. On a big endian machine, this 1st byte is always going to be zero. I have put together a patch that explicitly converts the uint32 to a uint8 to avoid this issue. Feedback is appreciated. Bugs closed To Be Determined mpi Boost 1.54.0 Showstopper fixed mpi, endian