Question regarding lxqt-panel

Hi all, :wave:

I just ran into a curious problem:

I had cause to restart the lxqt-panel process (I´m on Lubuntu) and tried it this way:

From the commad line I got the PID of the running process, which was 4235:

ps aux | grep lxqt-panel
rosika      4235  0.1  1.0 740680 43328 ?        Rl   12:27   0:33 /usr/bin/lxqt-panel
rosika     38364  0.0  0.0   9412   720 pts/4    S+   17:28   0:00 grep --color=auto lxqt-panel

Then I thought I could kill and restart the process with this command:

kill 4235; and sleep 2; and /usr/bin/lxqt-panel

(BTW: in fish-shell “; and” equals “&&” in bash)

To my surprise I got this output :hushed: :

rosika@rosika-10159 /m/r/f/D/D/w/d/ddgr-1.9> kill 4235; and sleep 2; and /usr/bin/lxqt-panel
 (0x7ffde96c3560) Warning: Icon theme "elementary" not found.
 (0x7ffde96c3560) Debug: ()
 (0x7ffde96c3560) Debug: WinIdChange 3e00008 handle QWidgetWindow(0x5606ae9812a0, name="LXQtPanel panel1Window") QScreen(0x5606ae69d420, name="VGA-1")
 (0x7ffde96c3560) Debug: Systray started
 (0x7ffde96c3560) Debug: Error on DBus request: QDBusError("org.freedesktop.DBus.Error.InvalidArgs", "No such property “ToolTip”")
 (0x7ffde96c3560) Debug: Error on DBus request: QDBusError("org.freedesktop.DBus.Error.InvalidArgs", "No such property “OverlayIconName”")
 (0x7ffde96c3560) Debug: Error on DBus request: QDBusError("org.freedesktop.DBus.Error.InvalidArgs", "No such property “OverlayIconPixmap”")
 (0x7ffde96c3560) Debug: Error on DBus request: QDBusError("org.freedesktop.DBus.Error.InvalidArgs", "No such property “AttentionIconPixmap”")
 (0x7ffde96c3560) Debug: Error on DBus request: QDBusError("org.freedesktop.DBus.Error.InvalidArgs", "No such property “ToolTip”")
 (0x7ffde96c3560) Debug: Error on DBus request: QDBusError("org.freedesktop.DBus.Error.InvalidArgs", "No such property “OverlayIconName”")
 (0x7ffde96c3560) Debug: Error on DBus request: QDBusError("org.freedesktop.DBus.Error.InvalidArgs", "No such property “OverlayIconPixmap”")
 (0x7ffde96c3560) Debug: Error on DBus request: QDBusError("org.freedesktop.DBus.Error.InvalidArgs", "No such property “AttentionIconPixmap”")
^C⏎

lxqt-panel was killed alright but it wasn´t restarted; it seems I was caught in an infinite loop or something. I had to cancel all that with ctrl + C . :thinking:

Luckily I was able to start the panel again by punching in the command lxqt-panel in the popup window created by “SuperKey + R” (for directly launching a process).

Still, I´d like to know what went wrong with my first attempt. :thinking:

Can anyone shed some light on the matter?

Thanks a lot in advance.

Many greetings
Rosika :slightly_smiling_face:

Sometimes it’s killed but not “killed”. I would’ve changed the 2 second sleep to a 20 second sleep. This would assure that the issue has nothing to do with an old instance still running.

1 Like

Its a daemon process. Needs to be in background.
Try /usr/bin/lxqt-panel &

Also it might need root privileges
Also check if it needs options

Regards
Neville

1 Like

Hi @Akito and @nevj , :wave:

thanks a lot to both of you for your replies. :heart:

@Akito:

Oh, that´s just great. Thanks so much. Indeed it worked. :+1:

I still got those messages:

kill 1461; and sleep 20; and /usr/bin/lxqt-panel
 (0x7fffdce2d520) Warning: Icon theme "elementary" not found.
 (0x7fffdce2d520) Debug: ()
 (0x7fffdce2d520) Debug: WinIdChange 1400008 handle QWidgetWindow(0x55a254e83590, name="LXQtPanel panel1Window") QScreen(0x55a254ba4420, name="VGA-1")
 (0x7fffdce2d520) Debug: Systray started
 (0x7fffdce2d520) Debug: Error on DBus request: QDBusError("org.freedesktop.DBus.Error.InvalidArgs", "No such property “ToolTip”")
[...]                                              
^C⏎

but at least this time the panel started.
Of course, when exiting with ctrl + C it was closed again. @nevj is rightly pointing out
it needs to be in background.

@nevj:

Thanks Neville for mentioning that. I wasn´t thinking about that, I have to admit.
I looked upon it as just another process … :blush:

I guess it´s all clear now.

Thank you very much @Akito and @nevj for your kind help.

Many greetings
Rosika :slightly_smiling_face:

1 Like

According to the developer of the application, these are unimportant messages, because they are logged on the Debug level. I guess, there is just a loop checking for available options and it says “error”, because it did not find certain options to be available, however that’s not breaking the application.

1 Like

Hi @Akito, :wave:

thank you so much for putting so much effort into getting some additional info. :heart:

That´s very interesting.
But how did you obtain this information, if I may ask?

I was taking a look at the man-pages, where a link is given for reporting bugs. It´s a github link.
Taking that as a starting point I arrived at GitHub - lxqt/lxqt: Checkout all LXQt components at once by using git submodule. .
Might this be your source?

Many greetings
Rosika :slightly_smiling_face:

You provided it yourself.

The log messages are prefixed with “Debug”.

2 Likes

@Akito:

Oh, I see. How embarassing. :upside_down_face:
I see that the messages are prefixed with “Debug” but I surely wouldn´t have been able to deduce that they were “unimportant messages”.

Correctly assessing such things clearly shows your expertise. :+1:

Thanks a lot for your help, Akito.

Many greetings from Rosika :slightly_smiling_face:

3 Likes