Dear Maintainer,
I have been trying to use gnome-panel to figure out which applications
are running at the same time in gnome-flashback but haven't been able
to. One of the things the bottom panel used to be able to do a year or
two ago was the ability to figure out at a glance how many windows
(i.e. GUI apps.) are running at the same time and switch between them.

While I'm able to switch them via gnome-control-center > Keyboard >
Shortcuts > Navigation > Switch Applications, I can't see them on the
panel.

I also tried to add workspace switcher but even that doesn't work.

Looking forward to know.

Do you have “Window list” applet in the “Add to panel” list? If yes,
what happens when you add it?

at bottom :-

I have the applet. I try to add it and nothing happens. I have clicked
it many times with no response esp. on the bottom panel.

On the top panel, the applet works as intended. I have removed the
bottom panel number of times and tried start from scratch with adding
the window list applet but to no result.

I have had several oddities happening.

For instance, if I want to add the clock applet to the panel, I have
to attempt it at least 2-3 times.

The notification applet doesn't get added anymore.

I guess the last two I need to file separate bug reports.

Is there someway to figure out things ?

Control: tags -1 unreproducible

I have two systems, one with Debian sid and one with Ubuntu Trusty,
and I cannot reproduce your issue on both of them.

So, unfortunately, there is nothing I can help you with at this point.

Hi!

I'm experiencing what seems to be the same issue: I did a Debian testing
dist-upgrade (it's been several weeks), rebooted, accidentally logged in
with a "regular" GNOME session, logged out, logged in again with a
"flashback" session (which I'm normally using), and now the panel at the
bottom is solid black.

Trying to re-add the regular widgets to it (workspace switcher, and so
on), just nothing happens.  Removing the bottom panel and then
re-creating it also doesn't help.  Reverting to an earlier version of
gnome-panel and gnome-panel-data (for example, 3.4.2.1-6) doesn't help.
Removing GNOME's dot-files in $HOME and having them be re-created upon
the next login doesn't help.

Adding widgets to the top panel works fine.


Grüße,
 Thomas

How about downgrading libgtk-3-0 and libglib2.0-0 ?

Hi all,
Both the bugs seem to be saying the same thing.

I just tried to run gnome-panel --replace in my gnome-flashback
session and came up with this :-

$ gnome-panel --replace

(gnome-panel:13588): Gtk-CRITICAL **:
gtk_accelerator_parse_with_keycode: assertion 'accelerator != NULL'
failed

** (gnome-panel:13588): WARNING **: Unable to parse mouse modifier '(null)'


(gnome-panel:13588): GLib-GIO-CRITICAL **:
g_dbus_connection_call_internal: assertion '(parameters == NULL) ||
g_variant_is_of_type (parameters, G_VARIANT_TYPE_TUPLE)' failed

and it just hangs in there.

There are no panels and can't do anything except do :-

gnome-session-save --kill --silent

From https://superuser.com/questions/713313/how-to-log-out-current-user

Hi all,
After yesterday's round of updates which included updates to the
kernel, rebooted today. This time there was a window list at the
bottom panel but the top panel was empty. So I removed the top panel
and started to populate it again, after adding some items the bottom
panel again became empty.

I removed both the top and bottom panels and tried using the
gnome-replace CLI and this time had the same replies as Andres
Martinez Quijano got at
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=744755#29

$ gnome-panel --replace

(gnome-panel:3008): Gtk-CRITICAL **:
gtk_accelerator_parse_with_keycode: assertion 'accelerator != NULL'
failed

** (gnome-panel:3008): WARNING **: Unable to parse mouse modifier '(null)'


(gnome-panel:3008): Gtk-CRITICAL **:
gtk_accelerator_parse_with_keycode: assertion 'accelerator != NULL'
failed

** (gnome-panel:3008): WARNING **: Unable to parse mouse modifier '(null)'

*** BUG ***
In pixman_region32_init_rect: Invalid rectangle passed
Set a breakpoint on '_pixman_log_error' to debug

*** BUG ***
In pixman_region32_init_rect: Invalid rectangle passed
Set a breakpoint on '_pixman_log_error' to debug

*** BUG ***
In pixman_region32_init_rect: Invalid rectangle passed
Set a breakpoint on '_pixman_log_error' to debug

*** BUG ***
In pixman_region32_init_rect: Invalid rectangle passed
Set a breakpoint on '_pixman_log_error' to debug

*** BUG ***
In pixman_region32_init_rect: Invalid rectangle passed
Set a breakpoint on '_pixman_log_error' to debug

Eventually, I was able to have both the window list and the top-panel
but it seems to be fragile.

I do see gnome-panel-dbg package and have installed it. Would try to
see if it gives more info. next time I run into this issue.

Hi all,
I again had issues after a reboot. This time didn't get any
panel/object in either the top gnome-panel or the bottom-panel.

Running gnome-panel --replace via gdb also didn't get/fetch anything except :-

$ gdb gnome-panel
GNU gdb (GDB) 7.6.2 (Debian 7.6.2-1.1)
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/bin/gnome-panel...Reading symbols from
/usr/lib/debug/usr/bin/gnome-panel...done.
done.
(gdb) run --replace
Starting program: /usr/bin/gnome-panel --replace
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffeb5d8700 (LWP 13863)]
[New Thread 0x7fffe928a700 (LWP 13864)]

(gnome-panel:13859): Gtk-CRITICAL **:
gtk_accelerator_parse_with_keycode: assertion 'accelerator != NULL'
failed

** (gnome-panel:13859): WARNING **: Unable to parse mouse modifier '(null)'

[New Thread 0x7fffe886c700 (LWP 13865)]
Traceback (most recent call last):
  File "/usr/share/gdb/auto-load/usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.20-gdb.py",
line 59, in <module>
    from libstdcxx.v6.printers import register_libstdcxx_printers
  File "/usr/lib/x86_64-linux-gnu/../../share/gcc-4.9/python/libstdcxx/v6/printers.py",
line 392
    raise ValueError, "Unsupported implementation for %s" % str(node.type)
                    ^
SyntaxError: invalid syntax
[New Thread 0x7fffcb7d1700 (LWP 13866)]
[New Thread 0x7fffcafd0700 (LWP 13867)]
[New Thread 0x7fffca7cf700 (LWP 13868)]

(gnome-panel:13859): Gtk-CRITICAL **:
gtk_accelerator_parse_with_keycode: assertion 'accelerator != NULL'
failed

** (gnome-panel:13859): WARNING **: Unable to parse mouse modifier '(null)'


(gnome-panel:13859): GLib-GObject-WARNING **:
/tmp/buildd/glib2.0-2.40.0/./gobject/gsignal.c:2462: signal
'size_request' is invalid for instance '0x1266450' of type 'GtkLabel'
[Thread 0x7fffca7cf700 (LWP 13868) exited]
[Thread 0x7fffcafd0700 (LWP 13867) exited]
[Thread 0x7fffcb7d1700 (LWP 13866) exited]
[New Thread 0x7fffcb7d1700 (LWP 13873)]
[Thread 0x7fffcb7d1700 (LWP 13873) exited]
[New Thread 0x7fffcb7d1700 (LWP 13874)]
*** BUG ***
In pixman_region32_init_rect: Invalid rectangle passed
Set a breakpoint on '_pixman_log_error' to debug

*** BUG ***
In pixman_region32_init_rect: Invalid rectangle passed
Set a breakpoint on '_pixman_log_error' to debug

*** BUG ***
In pixman_region32_init_rect: Invalid rectangle passed
Set a breakpoint on '_pixman_log_error' to debug

[Thread 0x7fffcb7d1700 (LWP 13874) exited]

If somebody can share how to set 'the breakpoint' at whichever place
it wants, maybe we get more clues.

Looking forward to know how.

Hi all,
Another reboot and saw that the bottom-panel does have 'window-list'
panel but somehow was added twice, so each window was being listed, be
it the browser (iceweasel) or nautilus. The way to remove the
additional window-list is to go to the left-hand side of the first
window-list and press CTRL+Right-click and choose Remove from panel.

The top panel though remains empty as can be seen. The only way
forward is to remove the old panel and make a new panel and the cycle
repeats itself with each reboot.

So to repeat (and this is after 5-6 reboots and examining the
behavior), the bottom-panel window-list and workspace switcher work
while the top panel remains empty . I cannot add items to the panel
and nothing is shown on the top panel as shared in the picture
attached. The only way to do that is to remove the top-panel and make
a new top panel with the shortcuts and whatever panels you like (the
behavior is for that session only.)

Hi,

Just to add to this.  I have just updated from stable to sid and
experienced the same. The bottom panel shows nothing in it at all;
"Add to panel..." does nothing.  I was able to get a functioning system
by adding the window list to the top panel.

Also, maybe related and maybe not, at first gnome did not refresh the
screen with windows moves or iconizing, menu manipulations, etc, leaving
much cruft behind.  That stops by enabling desktop icons.  But setting a
desktop background does not work (it is simply bland off-white).

I may have old gnome settings that are interferring.  I could create a
new user to test that theory out.

Thanks,
Peter

Tested with new user:  Behavior the same; Bottom panel is broken on
flashback and works on classic.

Can anyone confirm if this still happens with gnome-panel 3.38 or newer?