gnome-control-center bluetooth panel broken with i3

[Daniele Varrazzo]

piro@makkuro:~$ lsb_release -rd
Description: Ubuntu 18.04.2 LTS
Release: 18.04

gnome-control-center doesn't display bluetooth adapter when run under i3: the panel only shows the text:

```
No Bluetooth Found
Plug in a dongle to use Bluetooth.
```

Adapters are correctly displayed if the same user connects with gnome. Other panels work correctly in i3.

Running the panel from command line, when the tab is selected, the following log is displayed:

```
piro@makkuro:~$ XDG_CURRENT_DESKTOP=ubuntu:GNOME gnome-control-center

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_get_type: assertion 'value != NULL' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_type_is_subtype_of: assertion 'g_variant_type_check (type)' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_get_boolean: assertion 'g_variant_is_of_type (value, G_VARIANT_TYPE_BOOLEAN)' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_unref: assertion 'value != NULL' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_get_type: assertion 'value != NULL' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_type_is_subtype_of: assertion 'g_variant_type_check (type)' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_get_boolean: assertion 'g_variant_is_of_type (value, G_VARIANT_TYPE_BOOLEAN)' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_unref: assertion 'value != NULL' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_get_type: assertion 'value != NULL' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_type_is_subtype_of: assertion 'g_variant_type_check (type)' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_get_boolean: assertion 'g_variant_is_of_type (value, G_VARIANT_TYPE_BOOLEAN)' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_unref: assertion 'value != NULL' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_get_type: assertion 'value != NULL' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_type_is_subtype_of: assertion 'g_variant_type_check (type)' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_get_boolean: assertion 'g_variant_is_of_type (value, G_VARIANT_TYPE_BOOLEAN)' failed

(gnome-control-center:9355): GLib-CRITICAL **: 19:44:43.226: g_variant_unref: assertion 'value != NULL' failed
```

other tabs don't display any message at critical level.

[Daniele Varrazzo (daniele-varrazzo)]

Note: bluetooth does work in the same session: cli commands and blueman-applet allow using Bluetooth in the same session no problem.

[Sebastien Bacher (seb128)]

Thank you for your bug report, gnome-control-center isn't meant to be used outside of GNOME but you could still try to report the issue to the upstream on https://gitlab.gnome.org/GNOME/gnome-control-center/-/issues