1178 /usr/lib/virtualbox/VBoxXPCOMIPCD 1178 [Thread debugging using libthread_db enabled] Using host libthread_db library "/usr/lib/libthread_db.so.1". 0x00007f4a285b1cbb in poll () from /usr/lib/libc.so.6 Thread 1 (Thread 0x7f4a2a4f2680 (LWP 1178)): #0 0x00007f4a285b1cbb in poll () from /usr/lib/libc.so.6 #1 0x00007f4a2932803f in _pr_poll_with_poll (pds=0x55bd8cc73aa0 , npds=, timeout=300000) at /usr/local/src/virtualbox/trunk/src/VirtualBox-5.1.28/src/libs/xpcom18a4/nsprpub/pr/src/pthreads/ptio.c:3906 #2 0x00007f4a29329c96 in VBoxNsprPR_Poll (pds=, npds=, timeout=) at /usr/local/src/virtualbox/trunk/src/VirtualBox-5.1.28/src/libs/xpcom18a4/nsprpub/pr/src/pthreads/ptio.c:4308 #3 0x000055bd8ca70db5 in PollLoop (listenFD=0x55bd8ce38d20) at /usr/local/src/virtualbox/trunk/src/VirtualBox-5.1.28/src/libs/xpcom18a4/ipc/ipcd/daemon/src/ipcdUnix.cpp:377 #4 main (argc=, argv=) at /usr/local/src/virtualbox/trunk/src/VirtualBox-5.1.28/src/libs/xpcom18a4/ipc/ipcd/daemon/src/ipcdUnix.cpp:578