[regression] GTK apps hang for a long time on start-up under Xmir (and less under native Mir) failing to find dbus

[Daniel van Vugt]

$ /usr/games/sol

(sol:18808): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
Failed to connect to socket /tmp/dbus-7diijTV1R5: Connection refused
GConf Error: No D-BUS daemon running

(sol:18808): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
Failed to connect to socket /tmp/dbus-Zlu4hiB92O: Connection refused
GConf Error: No D-BUS daemon running

$ nautilus

(nautilus:18870): libunity-CRITICAL **: unity-launcher.vala:154: Unable to connect to session bus: Could not connect: Connection refused

(nautilus:18870): libunity-CRITICAL **: unity-launcher.vala:154: Unable to connect to session bus: Could not connect: Connection refused

(nautilus:18870): libunity-CRITICAL **: unity-launcher.vala:154: Unable to connect to session bus: Could not connect: Connection refused

(nautilus:18870): LIBDBUSMENU-GLIB-WARNING **: Unable to get session bus: Could not connect: Connection refused

(nautilus:18870): LIBDBUSMENU-GLIB-WARNING **: Unable to get session bus: Could not connect: Connection refused

(nautilus:18870): LIBDBUSMENU-GLIB-WARNING **: Unable to get session bus: Could not connect: Connection refused

[Daniel van Vugt (vanvugt)]

It used to work immediately in xenial. Now in yakkety I get errors every time.

Only dbus-related apps are affected. Native X11/Mir apps start instantly.

[Daniel van Vugt (vanvugt)]

I do have the daemons running. Only GTK apps can't find it....

message+ 2503 0.0 0.0 44676 5704 ? Ss 11:43 0:01 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation
dan 10940 0.0 0.0 43664 4568 ? Ss 15:21 0:00 dbus-daemon --session --address=unix:abstract=/tmp/dbus-VcCjNiW11q

Interesting the sol errors show it's looking for the wrong unix: socket path.

[Daniel van Vugt (vanvugt)]

Actually it's only really slow under Xmir. Native Mir gets the same errors but no delay...

Xmir:

$ /usr/games/sol

(sol:18808): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
Failed to connect to socket /tmp/dbus-7diijTV1R5: Connection refused
GConf Error: No D-BUS daemon running

(sol:18808): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
Failed to connect to socket /tmp/dbus-Zlu4hiB92O: Connection refused
GConf Error: No D-BUS daemon running

Mir:

$ /usr/games/sol

(sol:20759): Gtk-WARNING **: GtkSettings Cursor Theme: Unsupported GDK backend

(sol:20759): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
Unable to autolaunch a dbus-daemon without a $DISPLAY for X11
GConf Error: No D-BUS daemon running

(sol:20759): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
Unable to autolaunch a dbus-daemon without a $DISPLAY for X11
GConf Error: No D-BUS daemon running

[Daniel van Vugt (vanvugt)]

Yep, the apps are just failing to detect the session bus address of the Unity8 login.

Workaround for Unity8:
1. Find the real address: ps auxw | grep 'dbus-daemon --session'
2. env DBUS_SESSION_BUS_ADDRESS=...

Workaround for native Mir demo shells that have no dbus:
None?

[Sebastien Bacher (seb128)]

thank you for your bug report, could you get a backtrace of a process while hanging so we get an idea where it's blocked?

[Daniel van Vugt (vanvugt)]

I'm just going to assume this is a duplicate of bug 1604872 until proven otherwise.

[Sebastien Bacher (seb128)]

that would be weird, are the binaries you are trying apparmor confined? we don't have many of those, starting a game for sure shouldn't hit that ... do you have apparmor denials in your syslog?

[Daniel van Vugt (vanvugt)]

The yakkety fix for bug 1604872 has not solved this. So no longer a duplicate.

[Daniel van Vugt (vanvugt)]

Confirmed in all cases it's just that the X11/Xmir apps can't detect the session bus address of the login (which is on a different TTY BTW). Forcing DBUS_SESSION_BUS_ADDRESS solves the problem.

Here are some stack traces of the hangs:

gedit:
(gdb) bt
#0 0x00007ffff705e853 in select () at ../sysdeps/unix/syscall-template.S:84
#1 0x00007ffff477acd1 in g_spawn_sync ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007ffff477b313 in g_spawn_command_line_sync ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007ffff7862b70 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4 0x00007ffff78645f2 in g_dbus_address_get_for_bus_sync ()
   from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#5 0x00007ffff786f7ee in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#6 0x00007ffff787522b in g_bus_get_sync ()
   from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#7 0x00007ffff784b969 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#8 0x00007ffff78488f3 in g_application_register ()
   from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#9 0x00007ffff784918f in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#10 0x00007ffff78494f2 in g_application_run ()
   from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#11 0x0000000000400cfa in main ()

nautilus:
(gdb) bt
#0 0x00007ffff34c9833 in __select_nocancel ()
    at ../sysdeps/unix/syscall-template.S:84
#1 0x00007ffff418ecd1 in g_spawn_sync ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007ffff418f313 in g_spawn_command_line_sync ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007ffff4729b70 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4 0x00007ffff472b5f2 in g_dbus_address_get_for_bus_sync ()
   from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#5 0x00007ffff47367ee in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#6 0x00007ffff473c22b in g_bus_get_sync ()
   from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#7 0x00007ffff4712969 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#8 0x00007ffff470f8f3 in g_application_register ()
   from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#9 0x000000000042c78e in ?? ()
#10 0x00007fffedd29e40 in ffi_call_unix64 ()
   from /usr/lib/x86_64-linux-gnu/libffi.so.6
#11 0x00007fffedd298ab in ffi_call ()
   from /usr/lib/x86_64-linux-gnu/libffi.so.6
#12 0x00007ffff441fcf5 in g_cclosure_marshal_generic_va ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#13 0x00007ffff441f1d4 in ?? ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#14 0x00007ffff44394b8 in g_signal_emit_valist ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#15 0x00007ffff443a08f in g_signal_emit ()
   from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#16 0x00007ffff4710168 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#17 0x00007ffff47104f2 in g_application_run ()
   from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#18 0x000000000042ba31 in ?? ()
#19 0x00007ffff33ed7e0 in __libc_start_main (main=0x42b970, argc=1,
    argv=0x7fffffffe5b8, init=<optimised out>, fini=<optimised out>,
    rtld_fini=<optimised out>, stack_end=0x7fffffffe5a8)
    at ../csu/libc-start.c:291
#20 0x000000000042ba99 in ?? ()

/u...