Bug#906799: gnome-control-center/experimental: crashes on a qemu VM: cc_shell_model_set_panel_visibility: assertion failed: (valid)

[Simon McVittie]

Package: gnome-control-center
Version: 1:3.29.90-1
Severity: important

While trying to reproduce #906750 I found that gnome-control-center from
experimental doesn't start in a qemu VM, possibly because the VM does not
have any wifi devices:

user at host:~$ DISPLAY=:0 gdb gnome-control-center
...
ERROR:../shell/cc-shell-model.c:458:cc_shell_model_set_panel_visibility: assertion failed: (valid)

Thread 1 "gnome-control-c" received signal SIGABRT, Aborted.
__GI_raise (sig=sig at entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
51	../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0  __GI_raise (sig=sig at entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
#1  0x00007ffff1a622f1 in __GI_abort () at abort.c:79
#2  0x00007ffff7729fa5 in g_assertion_message () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff772a00a in g_assertion_message_expr () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00005555556a2af1 in cc_shell_model_set_panel_visibility (self=0x555555efbd60,
    id=id at entry=0x5555556c6ba5 "wifi", visibility=visibility at entry=CC_PANEL_VISIBLE_IN_SEARCH)
    at ../shell/cc-shell-model.c:458
#5  0x0000555555666254 in update_panel_visibility (client=<optimized out>) at ../panels/network/cc-wifi-panel.c:112
#6  0x0000555555666ebe in cc_wifi_panel_static_init_func () at ../panels/network/cc-wifi-panel.c:141
#7  0x00005555555abbb3 in cc_panel_loader_fill_model (model=0x555555efbd60) at ../shell/cc-panel-loader.c:214
#8  0x00005555555afcc8 in setup_model (shell=0x5555560e23b0) at ../shell/cc-shell-model.h:31
#9  cc_window_constructed (object=0x5555560e23b0) at ../shell/cc-window.c:767
#10 0x00007ffff79e2760 in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#11 0x00007ffff79e4420 in g_object_new_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#12 0x00007ffff79e4799 in g_object_new () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#13 0x00005555555b036c in cc_window_new (application=0x555555a6e320, model=model at entry=0x555555efbd60)
    at ../shell/cc-window.c:885
#14 0x00005555555aa62a in cc_application_startup (application=0x555555a6e320) at ../shell/cc-application.c:265
#15 0x00007ffff79dcf6d in g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#16 0x00007ffff79efe0e in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#17 0x00007ffff79f83f5 in g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#18 0x00007ffff79f8e0f in g_signal_emit () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#19 0x00007ffff7cc30a2 in g_application_register () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#20 0x00007ffff7cc38b7 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#21 0x00007ffff7cc3c46 in g_application_run () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#22 0x00005555555a9c51 in main (argc=<optimized out>, argv=<optimized out>) at ../shell/main.c:57

The failing assertion is:

  /* If we don't find any panel with the given id, we'll iterate until
   * valid == FALSE, so we can use this variable to determine if the
   * panel was found or not. It is a programming error to try to set
   * the visibility of a non-existant panel.
   */
  g_assert (valid);

but perhaps the wifi panel doesn't always appear?

This does not seem to be the same crash as #906750 - installing
avahi-daemon, or installing gnome-core and all of gnome-control-center's
Recommends, does not fix it.

    smcv