#0  sem_post@@GLIBC_2.1 () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/sem_post.S:41
  [Error: ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/sem_post.S was not found in source tree]
#1  0x08153c1f in PyThread_release_lock (lock=0x0) at ../Python/thread_pthread.h:350
  [Error: ../Python/thread_pthread.h was not found in source tree]
#2  0x081e0800 in PyEval_ReleaseLock () at ../Python/ceval.c:265
  [Error: ../Python/ceval.c was not found in source tree]
#3  0xb6e1363b in pyg_toggle_notify (data=data@entry=0x9167c5c, object=object@entry=0x94aefd0, is_last_ref=is_last_ref@entry=0) at ../../../gi/_gobject/pygobject.c:605
  [Error: ../../../gi/_gobject/pygobject.c was not found in source tree]
#4  0xb71340fd in toggle_refs_notify (object=<optimized out>, is_last_ref=0) at /build/buildd/glib2.0-2.37.93/./gobject/gobject.c:2906
  [Error: /build/buildd/glib2.0-2.37.93/./gobject/gobject.c was not found in source tree]
#5  0xb71341b8 in g_object_ref (_object=0x94aefd0) at /build/buildd/glib2.0-2.37.93/./gobject/gobject.c:3069
  [Error: /build/buildd/glib2.0-2.37.93/./gobject/gobject.c was not found in source tree]
#6  0xb6f53af2 in g_settings_backend_dispatch_signal (backend=backend@entry=0x8fb4a88, function_offset=function_offset@entry=0, name=name@entry=0xb4903188 "/org/gnome/shell/window-switcher/app-icon-mode", data1=data1@entry=0x0, data1_copy=0xb6f537c0 <pointer_id>, data1_copy@entry=0x0, data1_free=0xb6f537d0 <pointer_ignore>, data1_free@entry=0x0, data2=data2@entry=0x0) at /build/buildd/glib2.0-2.37.93/./gio/gsettingsbackend.c:329
  [Error: /build/buildd/glib2.0-2.37.93/./gio/gsettingsbackend.c was not found in source tree]
#7  0xb6f540dd in g_settings_backend_changed (backend=0x8fb4a88, key=key@entry=0xb4903188 "/org/gnome/shell/window-switcher/app-icon-mode", origin_tag=origin_tag@entry=0x0) at /build/buildd/glib2.0-2.37.93/./gio/gsettingsbackend.c:400
  [Error: /build/buildd/glib2.0-2.37.93/./gio/gsettingsbackend.c was not found in source tree]
#8  0xb52b90e9 in dconf_engine_change_notify (engine=engine@entry=0x90a2e18, prefix=0xb4903188 "/org/gnome/shell/window-switcher/app-icon-mode", changes=0xb4901a78, tag=0xb49031b9 ":1.12:user:80", origin_tag=origin_tag@entry=0x0, user_data=0x8fa62c0) at dconfsettingsbackend.c:250
  [Error: dconfsettingsbackend.c was not found in source tree]
#9  0xb52ba543 in dconf_engine_handle_dbus_signal (type=G_BUS_TYPE_SESSION, sender=0xb5523c90 ":1.12", path=0xb55228e8 "/ca/desrt/dconf/Writer/user", member=0xb5518318 "Notify", body=0x964f130) at dconf-engine.c:1164
  [Error: dconf-engine.c was not found in source tree]
#10 0xb6f66506 in emit_signal_instance_in_idle_cb (data=data@entry=0xb5523d50) at /build/buildd/glib2.0-2.37.93/./gio/gdbusconnection.c:3743
  [Error: /build/buildd/glib2.0-2.37.93/./gio/gdbusconnection.c was not found in source tree]
#11 0xb7060630 in g_idle_dispatch (source=source@entry=0xb5523968, callback=0xb6f66470 <emit_signal_instance_in_idle_cb>, user_data=0xb5523d50) at /build/buildd/glib2.0-2.37.93/./glib/gmain.c:5250
  [Error: /build/buildd/glib2.0-2.37.93/./glib/gmain.c was not found in source tree]
#12 0xb70638ce in g_main_dispatch (context=0x8fcfeb0) at /build/buildd/glib2.0-2.37.93/./glib/gmain.c:3065
  [Error: /build/buildd/glib2.0-2.37.93/./glib/gmain.c was not found in source tree]
#13 g_main_context_dispatch (context=context@entry=0x8fcfeb0) at /build/buildd/glib2.0-2.37.93/./glib/gmain.c:3641
  [Error: /build/buildd/glib2.0-2.37.93/./glib/gmain.c was not found in source tree]
#14 0xb7063c78 in g_main_context_iterate (context=context@entry=0x8fcfeb0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/buildd/glib2.0-2.37.93/./glib/gmain.c:3712
  [Error: /build/buildd/glib2.0-2.37.93/./glib/gmain.c was not found in source tree]
#15 0xb7063d38 in g_main_context_iteration (context=context@entry=0x8fcfeb0, may_block=may_block@entry=1) at /build/buildd/glib2.0-2.37.93/./glib/gmain.c:3773
  [Error: /build/buildd/glib2.0-2.37.93/./glib/gmain.c was not found in source tree]
#16 0xb52bbf70 in dconf_gdbus_worker_thread (user_data=0x8fcfeb0) at dconf-gdbus-thread.c:81
  [Error: dconf-gdbus-thread.c was not found in source tree]
#17 0xb7089f2a in g_thread_proxy (data=0xb55033b0) at /build/buildd/glib2.0-2.37.93/./glib/gthread.c:798
  [Error: /build/buildd/glib2.0-2.37.93/./glib/gthread.c was not found in source tree]
#18 0xb7751d78 in start_thread (arg=0xb52b5b40) at pthread_create.c:311
  [Error: pthread_create.c was not found in source tree]
#19 0xb768945e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131
  [Error: ../sysdeps/unix/sysv/linux/i386/clone.S was not found in source tree]