The fix for this bug provided in 1.8.9-1~exp2 has cause me a good deal of headache today.
For me, the issue is triggered as some C++ code containing: #include <hdf5.h> // sets OMPI_SKIP_MPICXX 1 #include <mpi.h> // MPI C++ namespace now is NOT available Note that even trying to unset OMPI_SKIP_MPICXX before including mpi.h won't work because OMPI_MPI_H will still be defined and the mpi.h header won't be processed again. I respectfully request that this patch be backed out until a better solution can be worked out. Totally disabling the MPI C++ bindings when including HDF5 is not an acceptable side effect. Regards, Brad