Here is a stackdump from inside the debugger (because it gives filenames and line numbers):
Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7f1eb6bfd700 (LWP 24847)] 0x000000366aa79252 in _int_malloc () from /lib64/libc.so.6 (gdb) bt #0 0x000000366aa79252 in _int_malloc () from /lib64/libc.so.6 #1 0x000000366aa7b7da in _int_realloc () from /lib64/libc.so.6 #2 0x000000366aa7baf5 in realloc () from /lib64/libc.so.6 #3 0x00007f1ee005d0a8 in epoll_dispatch (base=<value optimized out>, arg=0x13d1310, tv=<value optimized out>) at ../../../../../package/openmpi-1.6.5/opal/event/epoll.c:271 #4 0x00007f1ee005f1cf in opal_event_base_loop (base=0x13d1e50, flags=<value optimized out>) at ../../../../../package/openmpi-1.6.5/opal/event/event.c:838 #5 0x00007f1ee00842f9 in opal_progress () at ../../../../package/openmpi-1.6.5/opal/runtime/opal_progress.c:189 #6 0x00007f1ecd43cd7f in mca_pml_ob1_iprobe (src=<value optimized out>, tag=-1, comm=0x164dd40, matched=0x7f1eb6bfb8ac, status=0x7f1eb6bfb8b0) at ../../../../../../../package/openmpi-1.6.5/ompi/mca/pml/ob1/pml_ob1_iprobe.c:48 #7 0x00007f1edffe3427 in PMPI_Iprobe (source=227, tag=-1, comm=0x164dd40, flag=<value optimized out>, status=<value optimized out>) at piprobe.c:79 #8 0x00007f1eebb518e7 in OMPIConnection::Receive (this=0x13c7950, rMessage_p=std::vector of length 0, capacity 0, rMessageId_p=@0x7f1eb6bfc26c, NodeId_p=227)