Comment 56 for bug 1285444

I ran into this issue sporadically, but since yesterday I run into this issue every single time I try to login. In the past, rm -rf ~/.cache/compizconfig-1 helped.

Here's where compiz is sitting:

Thread 4 (Thread 0x7f27565f3700 (LWP 1900)):
#0 0x00007f27635749cd in read () at ../sysdeps/unix/syscall-template.S:84
#1 0x00007f2761deb740 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007f2761da7e84 in g_main_context_check () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007f2761da8340 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007f2761da8722 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5 0x00007f2757b50916 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#6 0x00007f2761dcebc5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#7 0x00007f27617396fa in start_thread (arg=0x7f27565f3700) at pthread_create.c:333
#8 0x00007f2763584b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f2757421700 (LWP 1885)):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00007f2761dec28c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007f2761da5d1d in g_source_attach () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007f2757b50cb8 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4 0x00007f2757b51318 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#5 0x00007f2757b3e02b in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#6 0x00007f2757b42326 in g_dbus_connection_send_message_with_reply () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#7 0x00007f2757b4278b in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#8 0x00007f2757b44f35 in g_dbus_connection_call () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#9 0x00007f275742918f in ?? () from /usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
#10 0x00007f2761da805a in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#11 0x00007f2761da8400 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#12 0x00007f2761da84ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#13 0x00007f275742928d in ?? () from /usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
#14 0x00007f2761dcebc5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007f27617396fa in start_thread (arg=0x7f2757421700) at pthread_create.c:333
#16 0x00007f2763584b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f275f90c700 (LWP 1859)):
#0 0x00007f2763578e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1 0x00007f2761da839c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007f2761da84ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007f2761da84e9 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007f2761dcebc5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5 0x00007f27617396fa in start_thread (arg=0x7f275f90c700) at pthread_create.c:333
#6 0x00007f2763584b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f276429a780 (LWP 1857)):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00007f2761dec28c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007f2757b44059 in g_dbus_connection_signal_subscribe () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#3 0x00007f2757b4d758 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4 0x00007f2757b4e3d0 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#5 0x00007f2757acaa1f in g_initable_new_valist () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#6 0x00007f2757acaad6 in g_initable_new () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#7 0x00007f2739aed0de in gvfs_dbus_mount_tracker_proxy_new_for_bus_sync () from /usr/lib/x86_64-linux-gnu/gvfs/libgvfscommon.so
#8 0x00007f2739d16c01 in ?? () from /usr/lib/x86_64-linux-gnu/gio/modules/libgvfsdbus.so
#9 0x00007f2739d17225 in ?? () from /usr/lib/x86_64-linux-gnu/gio/modules/libgvfsdbus.so
#10 0x00007f27607ce359 in g_type_create_instance () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#11 0x00007f27607b031b in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#12 0x00007f27607b1c01 in g_object_newv () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#13 0x00007f27607b2534 in g_object_new () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#14 0x00007f2757ace031 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#15 0x00007f2757ace1e0 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#16 0x00007f2757aba88e in g_file_new_for_path () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#17 0x00007f27419b2135 in gtk_css_provider_load_from_path () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#18 0x00007f27419b23fd in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#19 0x00007f2741ae1796 in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#20 0x00007f2741ae1bb4 in gtk_settings_get_for_screen () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#21 0x00007f2741a78e3f in ?? () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#22 0x00007f27607ae0a7 in g_cclosure_marshal_VOID__OBJECTv () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#23 0x00007f27607ab1d4 in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#24 0x00007f27607c59a6 in g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#25 0x00007f27607c608f in g_signal_emit () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#26 0x00007f27607ab1d4 in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#27 0x00007f27607c59a6 in g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#28 0x00007f27607c6555 in g_signal_emit_by_name () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#29 0x00007f27415b9655 in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#30 0x00007f27415935d6 in gdk_display_manager_open_display () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#31 0x00007f2741a50060 in gtk_init_check () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#32 0x00007f274238dbb4 in unity::UnityPluginVTable::init() () from /usr/lib/x86_64-linux-gnu/compiz/libunityshell.so
#33 0x00007f2763e6db72 in CompManager::initPlugin(CompPlugin*) () from /usr/lib/x86_64-linux-gnu/libcompiz_core.so.ABI-20151010
#34 0x00007f2763e6e5e1 in CompPlugin::push(CompPlugin*) () from /usr/lib/x86_64-linux-gnu/libcompiz_core.so.ABI-20151010
#35 0x00007f2763e3b817 in compiz::private_screen::PluginManager::updatePlugins(CompScreen*, std::vector<CompOption::Value, std::allocator<CompOption::Value> > const&) () from /usr/lib/x86_64-linux-gnu/libcompiz_core.so.ABI-20151010
#36 0x00007f2763e3bcc2 in PrivateScreen::processEvents() () from /usr/lib/x86_64-linux-gnu/libcompiz_core.so.ABI-20151010
#37 0x00007f2763e73ce7 in CompEventSource::callback() () from /usr/lib/x86_64-linux-gnu/libcompiz_core.so.ABI-20151010
#38 0x00007f27620c237f in Glib::Source::dispatch_vfunc(_GSource*, int (*)(void*), void*) () from /usr/lib/x86_64-linux-gnu/libglibmm-2.4.so.1
#39 0x00007f2761da805a in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#40 0x00007f2761da8400 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#41 0x00007f2761da8722 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#42 0x00007f2763e318cf in compiz::private_screen::EventManager::startEventLoop(_XDisplay*) () from /usr/lib/x86_64-linux-gnu/libcompiz_core.so.ABI-20151010
#43 0x00000000004017c1 in main ()

Maybe a race condition with loading dbus somehow?

Killing compiz makes the desktop load. Maybe re-building the .cache/compizconfig-1 directory changes timing enough to give dbus more time, and then it doesn't run into this situation?