gnome-control-center crashes testing sound effects with alert volume set to off

[John Leach]

1. open gnome-control-center
2. click "sound"
3. clock "sound effects" tab
4. set "alert volume" to "off" using the button on the right
5. select one of the alert sounds in the list
6. gnome-control-center segfaults

In fact, it looks like just clicking around the alert sounds with the alert volume on or off can trigger it.

ProblemType: Crash
DistroRelease: Ubuntu 14.04
Package: gnome-control-center 1:3.6.3-0ubuntu54
ProcVersionSignature: Ubuntu 3.13.0-19.40-generic 3.13.6
Uname: Linux 3.13.0-19-generic x86_64
ApportVersion: 2.13.3-0ubuntu1
Architecture: amd64
AssertionMessage: gnome-control-center.real: ../../src/xcb_io.c:298: poll_for_response: Assertion `!xcb_xlib_threads_sequence_lost' failed.
CurrentDesktop: GNOME
Date: Sat Mar 29 11:36:56 2014
ExecutablePath: /usr/bin/gnome-control-center.real
InstallationDate: Installed on 2014-03-28 (0 days ago)
InstallationMedia: Ubuntu-GNOME 14.04 LTS "Trusty Tahr" - Beta amd64 (20140326.1)
ProcCmdline: /usr/bin/gnome-control-center.real sound
Signal: 6
SourcePackage: gnome-control-center
StacktraceTop:
 __assert_fail_base (fmt=0x7f6b96309718 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x7f6b977f8390 "!xcb_xlib_threads_sequence_lost", file=file@entry=0x7f6b977f81db "../../src/xcb_io.c", line=line@entry=298, function=function@entry=0x7f6b977f86d0 "poll_for_response") at assert.c:92
 __GI___assert_fail (assertion=0x7f6b977f8390 "!xcb_xlib_threads_sequence_lost", file=0x7f6b977f81db "../../src/xcb_io.c", line=298, function=0x7f6b977f86d0 "poll_for_response") at assert.c:101
 ?? () from /usr/lib/x86_64-linux-gnu/libX11.so.6
 _XEventsQueued () from /usr/lib/x86_64-linux-gnu/libX11.so.6
 XPending () from /usr/lib/x86_64-linux-gnu/libX11.so.6
Title: gnome-control-center.real assert failure: gnome-control-center.real: ../../src/xcb_io.c:298: poll_for_response: Assertion `!xcb_xlib_threads_sequence_lost' failed.
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
usr_lib_gnome-control-center: deja-dup 30.0-0ubuntu2

[Apport retracing service (apport)]

StacktraceTop:
 __assert_fail_base (fmt=0x7f6b96309718 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x7f6b977f8390 "!xcb_xlib_threads_sequence_lost", file=file@entry=0x7f6b977f81db "../../src/xcb_io.c", line=line@entry=298, function=function@entry=0x7f6b977f86d0 <__PRETTY_FUNCTION__.14376> "poll_for_response") at assert.c:92
 __GI___assert_fail (assertion=assertion@entry=0x7f6b977f8390 "!xcb_xlib_threads_sequence_lost", file=file@entry=0x7f6b977f81db "../../src/xcb_io.c", line=line@entry=298, function=function@entry=0x7f6b977f86d0 <__PRETTY_FUNCTION__.14376> "poll_for_response") at assert.c:101
 poll_for_response (dpy=dpy@entry=0x24b79f0) at ../../src/xcb_io.c:296
 _XEventsQueued (dpy=dpy@entry=0x24b79f0, mode=mode@entry=2) at ../../src/xcb_io.c:363
 XPending (dpy=0x24b79f0) at ../../src/Pending.c:55

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.