Comment 2 for bug 853038

StacktraceTop:
 __cxxabiv1::__dynamic_cast (src_ptr=0x8bc0d00, src_type=0xb374f298, dst_type=0xb37545e0, src2dst=0) at ../../../../src/libstdc++-v3/libsupc++/dyncast.cc:61
 DebugDBusInterface::OnBusAcquired (connection=0x8bc9e30, name=0x89bb180 "com.canonical.Unity", data=0x8ad99a0) at /build/buildd/unity-4.16.0/plugins/unityshell/src/DebugDBusInterface.cpp:183
 connection_get_cb (source_object=0x0, res=0x8f39058, user_data=0x89bb138) at /build/buildd/glib2.0-2.29.90/./gio/gdbusnameowning.c:439
 g_simple_async_result_complete (simple=0x8f39058) at /build/buildd/glib2.0-2.29.90/./gio/gsimpleasyncresult.c:749
 complete_in_idle_cb (data=0x8f39058) at /build/buildd/glib2.0-2.29.90/./gio/gsimpleasyncresult.c:761