#0  0x00007fb6b5fc7227 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  0x00007fb6b5fc8e8a in __GI_abort () at abort.c:89
  [Error: abort.c was not found in source tree]
#2  0x00007fb6b5fbfffd in __assert_fail_base (fmt=0x7fb6b6121fa8 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x7fb695c5b95d "!xcb_xlib_unknown_req_in_deq", file=file@entry=0x7fb695c5b92b "../../src/xcb_io.c", line=line@entry=179, function=function@entry=0x7fb695c5be00 <__PRETTY_FUNCTION__.14515> "dequeue_pending_request") at assert.c:92
  [Error: assert.c was not found in source tree]
#3  0x00007fb6b5fc00b2 in __GI___assert_fail (assertion=assertion@entry=0x7fb695c5b95d "!xcb_xlib_unknown_req_in_deq", file=file@entry=0x7fb695c5b92b "../../src/xcb_io.c", line=line@entry=179, function=function@entry=0x7fb695c5be00 <__PRETTY_FUNCTION__.14515> "dequeue_pending_request") at assert.c:101
  [Error: assert.c was not found in source tree]
#4  0x00007fb695be8c9c in dequeue_pending_request (dpy=dpy@entry=0x7fb6281a3c00, req=req@entry=0x7fb6281b8e60) at ../../src/xcb_io.c:177
  [Error: xcb_io.c was not found in source tree]
#5  0x00007fb695be9b98 in _XReply (dpy=dpy@entry=0x7fb6281a3c00, rep=rep@entry=0x7fb63a663ad0, extra=extra@entry=0, discard=discard@entry=1) at ../../src/xcb_io.c:639
  [Error: xcb_io.c was not found in source tree]
#6  0x00007fb695bcff91 in XGetSelectionOwner (dpy=0x7fb6281a3c00, selection=336) at ../../src/GetSOwner.c:41
  [Error: GetSOwner.c was not found in source tree]
#7  0x00007fb68ec20bee in check_manager_window (client=0x7fb6281b6450) at /build/gtk+2.0-tESQz7/gtk+2.0-2.24.29/gdk/x11/xsettings-client.c:430
  [Error: xsettings-client.c was not found in source tree]
#8  0x00007fb68ec20fa1 in _gdk_xsettings_client_process_event (client=<optimized out>, xev=<optimized out>) at /build/gtk+2.0-tESQz7/gtk+2.0-2.24.29/gdk/x11/xsettings-client.c:597
  [Error: xsettings-client.c was not found in source tree]
#9  0x00007fb68ec069b3 in gdk_xsettings_client_event_filter (xevent=<optimized out>, event=<optimized out>, data=<optimized out>) at /build/gtk+2.0-tESQz7/gtk+2.0-2.24.29/gdk/x11/gdkevents-x11.c:3115
  [Error: gdkevents-x11.c was not found in source tree]
#10 0x00007fb68ec06ef1 in gdk_event_apply_filters (xevent=xevent@entry=0x7fb63a663d10, event=event@entry=0x7fb620003310, window=window@entry=0x7fb6b04456c0) at /build/gtk+2.0-tESQz7/gtk+2.0-2.24.29/gdk/x11/gdkevents-x11.c:371
  [Error: gdkevents-x11.c was not found in source tree]
#11 0x00007fb68ec082d6 in gdk_event_translate (display=display@entry=0x7fb6281b0040, event=event@entry=0x7fb620003310, xevent=xevent@entry=0x7fb63a663d10, return_exposes=return_exposes@entry=0) at /build/gtk+2.0-tESQz7/gtk+2.0-2.24.29/gdk/x11/gdkevents-x11.c:1074
  [Error: gdkevents-x11.c was not found in source tree]
#12 0x00007fb68ec09b76 in _gdk_events_queue (display=display@entry=0x7fb6281b0040) at /build/gtk+2.0-tESQz7/gtk+2.0-2.24.29/gdk/x11/gdkevents-x11.c:2358
  [Error: gdkevents-x11.c was not found in source tree]
#13 0x00007fb68ec09c1e in gdk_event_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at /build/gtk+2.0-tESQz7/gtk+2.0-2.24.29/gdk/x11/gdkevents-x11.c:2419
  [Error: gdkevents-x11.c was not found in source tree]
#14 0x00007fb68e695147 in g_main_context_dispatch () from /tmp/apport_sandbox_UtZkcj/lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007fb68e6953a0 in g_main_context_iterate.isra () from /tmp/apport_sandbox_UtZkcj/lib/x86_64-linux-gnu/libglib-2.0.so.0
#16 0x00007fb68e6956c2 in g_main_loop_run () from /tmp/apport_sandbox_UtZkcj/lib/x86_64-linux-gnu/libglib-2.0.so.0
#17 0x00007fb68f2be088 in ?? ()
#18 0x00007fb62802ac50 in ?? ()
#19 0x00007fb68e6bbb95 in g_thread_proxy () from /tmp/apport_sandbox_UtZkcj/lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007fb6b595d66a in start_thread (arg=0x7fb63a664700) at pthread_create.c:333
  [Error: pthread_create.c was not found in source tree]
#21 0x00007fb6b6098e4d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109
  [Error: clone.S was not found in source tree]