unity-panel-service crashed with SIGSEGV in g_dbus_proxy_call_internal()

[Nice Testhouse]

Release ubuntu 12.10 Quantal (Radeon) with ppa:SIL2100

Attached a 2nd monitor to the system and encountered system error notification.

ProblemType: Crash
DistroRelease: Ubuntu 12.10
Package: unity-services 6.0.0-0ubuntu5~test1 [origin: LP-PPA-sil2100-quantal]
ProcVersionSignature: Ubuntu 3.5.0-6.6-generic 3.5.0
Uname: Linux 3.5.0-6-generic i686
ApportVersion: 2.4-0ubuntu5
Architecture: i386
CompizPlugins: [core,composite,opengl,compiztoolbox,decor,vpswitch,snap,mousepoll,resize,place,move,wall,grid,regex,imgpng,session,gnomecompat,animation,fade,unitymtgrabhandles,workarounds,scale,expo,ezoom,unityshell]
CrashDB: unity
Date: Thu Jul 26 16:13:02 2012
ExecutablePath: /usr/lib/unity/unity-panel-service
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha i386 (20120713.1)
ProcCmdline: /usr/lib/unity/unity-panel-service
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, no user)
 LANGUAGE=en_GB:en
 LANG=en_GB.UTF-8
SegvAnalysis:
 Segfault happened at: 0xb7115470: mov 0x0(%ebp),%edx
 PC (0xb7115470) ok
 source "0x0(%ebp)" (0xaaaaaaaa) not located in a known VMA region (needed readable region)!
 destination "%edx" ok
SegvReason: reading unknown VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 ?? () from /usr/lib/i386-linux-gnu/libgio-2.0.so.0
 g_dbus_proxy_call () from /usr/lib/i386-linux-gnu/libgio-2.0.so.0
 ?? () from /usr/lib/i386-linux-gnu/libdbusmenu-glib.so.4
 ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
 g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
Title: unity-panel-service crashed with SIGSEGV in g_dbus_proxy_call()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

[Bilal Akhtar (bilalakhtar)]

Please don't mark a bug public until the retracer has retraced it.

[Apport retracing service (apport)]

StacktraceTop:
 g_dbus_proxy_call_internal (proxy=proxy@entry=0xaaaaaaaa, method_name=method_name@entry=0xb5a3f13a <Address 0xb5a3f13a out of bounds>, parameters=parameters@entry=0xb4f15348, flags=flags@entry=G_DBUS_CALL_FLAGS_NONE, timeout_msec=timeout_msec@entry=-1, fd_list=fd_list@entry=0x0, cancellable=cancellable@entry=0x0, callback=callback@entry=0, user_data=user_data@entry=0x0) at /build/buildd/glib2.0-2.33.6/./gio/gdbusproxy.c:2705
 g_dbus_proxy_call (proxy=0xaaaaaaaa, method_name=0xb5a3f13a <Address 0xb5a3f13a out of bounds>, parameters=0xb4f15348, flags=G_DBUS_CALL_FLAGS_NONE, timeout_msec=-1, cancellable=0x0, callback=0, user_data=0x0) at /build/buildd/glib2.0-2.33.6/./gio/gdbusproxy.c:3017
 ?? ()

[Bilal Akhtar (bilalakhtar)]

The stacktrace is missing a key line. This could probably be because the problem you're experiencing is with a third-party PPA. Can you confirm if this happens with Quantal repo packages too?

[Łukasz Zemczak (sil2100)]

Could be. Just for clarification: ppa:sil2100/quantal - which is the source of the installed package, is nothing else than lp:compiz trunk packages + distro fixes for enabling the gsettings framework. So besides the distro magic regarding gsettings, there is nothing else than compiz trunk. The unity package also had to be rebuild because of a necessary ABI bump. But essentially the unity package is the same as in quantal, just rebuilt against the new compiz.

[Steve Langasek (vorlon)]

> The stacktrace is missing a key line. This could probably
> be because the problem you're experiencing is with a
> third-party PPA. Can you confirm if this happens with
> Quantal repo packages too?

See bugs 1029442, 1029713, 1031203, and 1033267, which all show the same corrupted address (0xaaaaaaaaaaaaaaaa) in g_dbus_proxy_call_internal(). I don't know why the retracer doesn't consider them the same bug, but it's likely that they are.