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lxpanel infinite loop on vncserver start

Posted: Sun May 08, 2016 6:46 pm
by Gert
Hi All,

I'm setting up an RPI operating 100% headless. (This one has never seen a monitor/keyboad/mouse).
With VNC installed ...

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apt-get update
apt-get install tightvncserver
tightvncserver :1 -geometry 1280x1024 -depth 24
VNC session starts and is accessible.
BUT it turns out that the task panel does not show up. Instead lxpanel seems to be caught in an infinite startup->fail loop.

Here is output from 'top':

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top - 11:39:54 up 10:46,  1 user,  load average: 1.35, 0.50, 0.24
Tasks:  93 total,   3 running,  90 sleeping,   0 stopped,   0 zombie
%Cpu(s): 85.0 us, 13.7 sy,  0.0 ni,  0.0 id,  1.3 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem:    445376 total,   377340 used,    68036 free,   233568 buffers
KiB Swap:   102396 total,        0 used,   102396 free,    69928 cached

  PID USER      PR  NI  VIRT  RES  SHR S  %CPU %MEM    TIME+  COMMAND
 3334 gottsch   20   0 97384  16m  14m R  22.8  3.7   0:00.72 lxpanel
 3014 gottsch   20   0 19428  13m 2664 S  13.6  3.1   0:12.33 Xtightvnc
 3336 gottsch   20   0 16340 5400 5004 R   5.4  1.2   0:00.17 menu-cache-gen
 3138 gottsch   20   0  113m  19m  17m S   3.8  4.5   0:04.10 pcmanfm
PID of lxpanel steps up about every 2sec indicating that a new instance is launched and immediately fails.

This is a fresh image of the SD card using

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2015-05-05-raspbian-wheezy.img
(I don't like jessie)

What's the fix to get lxpanel running stable?

Thanks,
Gert

Re: lxpanel infinite loop on vncserver start

Posted: Sun May 08, 2016 11:11 pm
by stderr
Gert wrote:This is a fresh image of the SD card using

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2015-05-05-raspbian-wheezy.img
(I don't like jessie)
What's the fix to get lxpanel running stable?
I would find another sdcard and install jessie. Wheezy is end of life and even if it wasn't, you couldn't hurt yourself seeing if something worked with a more recent version, no point in wasting time with something that's already fixed.

Re: lxpanel infinite loop on vncserver start

Posted: Mon May 09, 2016 3:37 am
by Gert
Thank you @stderr for the post.

I respectfully object.

Hasn't anybody had a headless RPI working with proper VNC access ?
There must be a fix and it must be known for a long time.

A hint that might point someone to debug.

Going to the VNC, open a terminal and typing 'lxpanel' has two outcomes.
  • 1. gottsch@rpi2 ~ $ lxpanel
    Xlib: extension "RANDR" missing on display ":1.0".
    There is already an instance of LXPanel. Now to exit
  • 2. gottsch@rpi2 ~ $ lxpanel
    Xlib: extension "RANDR" missing on display ":1.0".
    ** Message: x-terminal-emulator has very limited support, consider choose another terminal
    ** (lxpanel:4279): WARNING **: The directory '~/Templates' doesn't exist, ignoring it
    (lxpanel:4279): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-can-change-accels after class was initialised
    (lxpanel:4279): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-menu-popup-delay after class was initialised
    (lxpanel:4279): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-menu-popdown-delay after class was initialised
    (lxpanel:4279): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-menu-images after class was initialised
    (lxpanel:4279): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-label-select-on-focus after class was initialised
    (lxpanel:4279): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-button-images after class was initialised
    (lxpanel:4279): Gtk-CRITICAL **: IA__gtk_misc_set_alignment: assertion 'GTK_IS_MISC (misc)' failed
    (lxpanel:4279): Gtk-CRITICAL **: IA__gtk_misc_set_alignment: assertion 'GTK_IS_MISC (misc)' failed
    ** (lxpanel:4279): WARNING **: launchbar: desktop entry does not exist
    ** (lxpanel:4279): WARNING **: launchtaskbar: can't init button
    ** (lxpanel:4279): WARNING **: launchbar: desktop entry does not exist
    ** (lxpanel:4279): WARNING **: launchtaskbar: can't init button
    (lxpanel:4279): Gtk-CRITICAL **: IA__gtk_misc_set_alignment: assertion 'GTK_IS_MISC (misc)' failed
    (lxpanel:4279): Wnck-WARNING **: Unhandled action type _OB_WM_ACTION_UNDECORATE
    (lxpanel:4279): Gtk-CRITICAL **: IA__gtk_misc_set_alignment: assertion 'GTK_IS_MISC (misc)' failed
    (lxpanel:4279): Wnck-WARNING **: Unhandled action type _OB_WM_ACTION_UNDECORATE
#1 seems to happen when an instance of lxpanel is just running. (which process starts it ?) It then seems to fail (for the below reaso in Xlib?) and gets started again by the parent. Nothin happens here.
Following #2 the panel shows up and all is stable until next reboot. Seems just by luck I hit a 'gap' between failed launches by the parent process and a 'proper' instance of lxpanel gets started.

Hint seems to be

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Xlib:  extension "RANDR" missing on display ":1.0".
What's going on in Xlib there?

Can anybody help?

Thanks,
Gert

Re: lxpanel infinite loop on vncserver start

Posted: Sat Sep 10, 2016 8:55 am
by oaksboard
hello gert,

exact same problem here! did take me some time to find out that lxpanel was continuously crashing.
the only thing you see on the remote desktop is the recycle bin, the raspberry logo in the background and an empty grey bar on top of the screen that continues to appear/disappear moving everything on screen down and up again.

is it possible that nobody had this issue or there is no fix for it?

by,
oskar

Re: lxpanel infinite loop on vncserver start

Posted: Sat Sep 10, 2016 9:14 am
by oaksboard
hello again,

found a solution here: https://bbs.archlinux.org/viewtopic.php?id=64603

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$ sudo cp /etc/xdg/lxsession/LXDE-pi/autostart /etc/xdg/lxsession/LXDE-pi/autostart-
$ sudo vi /etc/xdg/lxsession/LXDE-pi/autostart
and replace "@lxpanel --profile LXDE-pi" with "@lxpanel" alone (without profile), so that the file looks something like this:

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@lxpanel
@pcmanfm --desktop --profile LXDE-pi
@xscreensaver -no-splash
now it works for me.

bye,
oskar