#0  0x00007fed6dd76267 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55
  [Error: raise.c was not found in source tree]
#1  0x00007fed6dd77eca in __GI_abort () at abort.c:89
  [Error: abort.c was not found in source tree]
#2  0x00007fed6dd6f03d in __assert_fail_base (fmt=0x7fed6ded1028 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x7fed6e80d132 "*_head == _item", file=file@entry=0x7fed6e80d117 "entrygroup.c", line=line@entry=245, function=function@entry=0x7fed6e80d3b0 "avahi_entry_group_free") at assert.c:92
  [Error: assert.c was not found in source tree]
#3  0x00007fed6dd6f0f2 in __GI___assert_fail (assertion=0x7fed6e80d132 "*_head == _item", file=0x7fed6e80d117 "entrygroup.c", line=245, function=0x7fed6e80d3b0 "avahi_entry_group_free") at assert.c:101
  [Error: assert.c was not found in source tree]
#4  0x00007fed6e806a37 in avahi_entry_group_free () from /tmp/apport_sandbox_ge9Ymp/usr/lib/x86_64-linux-gnu/libavahi-client.so.3
#5  0x00005613a50102d2 in dnssdDeregisterInstance (srv=0x5613a662d9d0, from_callback=<optimized out>) at dirsvc.c:684
  679: 
  680: #  else /* HAVE_AVAHI */
  681:   if (!from_callback)
  682:     avahi_threaded_poll_lock(DNSSDMaster);
  683: 
  684:   avahi_entry_group_free(*srv);
  685: 
  686:   if (!from_callback)
  687:     avahi_threaded_poll_unlock(DNSSDMaster);
  688: #  endif /* HAVE_DNSSD */
  689: 
#6  0x00005613a5010352 in dnssdDeregisterPrinter (p=0x5613a662d230, clear_name=clear_name@entry=1, from_callback=from_callback@entry=1) at dirsvc.c:711
  706:                   "dnssdDeregisterPrinter(p=%p(%s), clear_name=%d)", p, p->name,
  707:                   clear_name);
  708: 
  709:   if (p->ipp_srv)
  710:   {
  711:     dnssdDeregisterInstance(&p->ipp_srv, from_callback);
  712: 
  713: #  ifdef HAVE_DNSSD
  714: #    ifdef HAVE_SSL
  715:     dnssdDeregisterInstance(&p->ipps_srv, from_callback);
  716: #    endif /* HAVE_SSL */
#7  0x00005613a5010868 in dnssdDeregisterAllPrinters (from_callback=from_callback@entry=1) at dirsvc.c:659
  654: 
  655:   for (p = (cupsd_printer_t *)cupsArrayFirst(Printers);
  656:        p;
  657:        p = (cupsd_printer_t *)cupsArrayNext(Printers))
  658:     if (!(p->type & (CUPS_PRINTER_REMOTE | CUPS_PRINTER_SCANNER)))
  659:       dnssdDeregisterPrinter(p, 1, from_callback);
  660: }
  661: 
  662: 
  663: /*
  664:  * 'dnssdDeregisterInstance()' - Deregister a DNS-SD service instance.
#8  0x00005613a5011bed in dnssdClientCallback (c=0x5613a6810e60, state=<optimized out>, userdata=<optimized out>) at dirsvc.c:602
  597: 
  598: 	 /*
  599: 	  * Unregister everything and close the client...
  600: 	  */
  601: 
  602: 	  dnssdDeregisterAllPrinters(1);
  603: 	  dnssdDeregisterInstance(&WebIFSrv, 1);
  604: 	  avahi_client_free(DNSSDClient);
  605: 	  DNSSDClient = NULL;
  606: 
  607: 	 /*
#9  0x00007fed6e805705 in ?? () from /tmp/apport_sandbox_ge9Ymp/usr/lib/x86_64-linux-gnu/libavahi-client.so.3
#10 0x00007fed6ec3c0e5 in dbus_connection_dispatch (connection=0x5613a680b3e0) at ../../dbus/dbus-connection.c:4703
  [Error: dbus-connection.c was not found in source tree]
#11 0x00007fed6e80c686 in ?? () from /tmp/apport_sandbox_ge9Ymp/usr/lib/x86_64-linux-gnu/libavahi-client.so.3
#12 0x00007fed6ea20638 in avahi_simple_poll_dispatch () from /tmp/apport_sandbox_ge9Ymp/usr/lib/x86_64-linux-gnu/libavahi-common.so.3
#13 0x00007fed6ea2091d in avahi_simple_poll_loop () from /tmp/apport_sandbox_ge9Ymp/usr/lib/x86_64-linux-gnu/libavahi-common.so.3
#14 0x00007fed6ea209e4 in ?? () from /tmp/apport_sandbox_ge9Ymp/usr/lib/x86_64-linux-gnu/libavahi-common.so.3
#15 0x00007fed6e1186aa in start_thread (arg=0x7fed6a1b0700) at pthread_create.c:333
  [Error: pthread_create.c was not found in source tree]
#16 0x00007fed6de47eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109
  [Error: clone.S was not found in source tree]