Hi, openmpi just had an ABI transition (libopenmpi1 -> libopenmpi1.3), and Boost has been built against the old version on amd64, powerpc, ia64 and i386. I have already binNMU'd the former two, leaving ia64 (which I don't have) and i386 (which I can do if needed). openmpi just had another upload and is buggy, so it's not likely to migrate soon, but if it were to migrate, this would be a blocker. Simon