Applet: Handle UnknownObject DBus error.

[tommie]

Every 10 s, I see this error, on Ubuntu 24.04.1, which uses Blueman 2.3.5:

 During handling of the above exception, another exception occurred:
 Traceback (most recent call last):
   File "/usr/lib/python3/dist-packages/blueman/main/Applet.py", line 97, in on_device_created
     plugin.on_device_created(path)
   File "/usr/lib/python3/dist-packages/blueman/plugins/applet/RecentConns.py", line 99, in on_device_created
     self._rebuild()
   File "/usr/lib/python3/dist-packages/blueman/plugins/applet/RecentConns.py", line 80, in _rebuild
     self._items = self._get_items()
                   ^^^^^^^^^^^^^^^^^
   File "/usr/lib/python3/dist-packages/blueman/plugins/applet/RecentConns.py", line 199, in _get_items
     return sorted(
            ^^^^^^^
   File "/usr/lib/python3/dist-packages/blueman/plugins/applet/RecentConns.py", line 213, in <genexpr>
     if i["adapter"] not in adapter_addresses or self._get_device_path(i["adapter"], i["address"])),
                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/lib/python3/dist-packages/blueman/plugins/applet/RecentConns.py", line 193, in _get_device_path
     device = self.parent.Manager.find_device(address, adapter.get_object_path())
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/lib/python3/dist-packages/blueman/bluez/Manager.py", line 146, in find_device
     if device['Address'] == address:
        ~~~~~~^^^^^^^^^^^
   File "/usr/lib/python3/dist-packages/blueman/bluez/Base.py", line 135, in __getitem__
     return self.get(key)
            ^^^^^^^^^^^^^
   File "/usr/lib/python3/dist-packages/blueman/bluez/Base.py", line 106, in get
     raise parse_dbus_error(e)
 blueman.bluez.errors.BluezDBusException: org.freedesktop.DBus.Error.UnknownObject Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist

Since there is already exception handling for the adaptor going away (c67ae92), it seems reasonable to add this, in case of devices that "flicker". I can't say for sure why my device is listed by the adapter, but don't actually exist.

(I've also had the applet pinned at 100% CPU, but I think that's a separate issue.)

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[infirit]

We should handle this error but I want to know why/how you got into this loop. Recentconns is notified of a new device which it may or may not know and tries to rebuild it's menu. It fails because the just created device doesn't exist anymore, which I find a little unusual.

Can you kill blueman-applet and run it from a terminal with blueman-applet --debug and let it log for a couple of minutes minute while this is going on and post/link it here?

[tommie]

I'll try to do that. This triggers very rarely, probably around suspend/resume. When it happens, it gets stuck repeating the same error every 10 s.

[infirit]

If it happens with suspend/resume it might be the adapter isn't restoring it's state properly on resume. Kernel log may also provide some clues then.

[infirit]

The change is fine. If you do find the time to get some logs I would still like to see them.

[tommie]

Thanks. :)

I've actually been running an unpatched Blueman since we last spoke, but haven't been able to trigger it. I only suspend 1-2 times a day, though. I'll get back to you when it happens.