unity-2d-panel crashes occasionally after launching NetBeans

[Jesse Glick]

As a NetBeans IDE developer, I am frequently launching the IDE (a Swing-based Java application) in one or more copies. From time to time when opening the IDE main window (i.e. a javax.swing.JFrame) while running Unity 2D, unity-2d-panel suddenly crashes, leaving a blank space (showing the screen background) where the panel normally is. The window manager continues to work, so I can switch between apps using Alt-TAB, but the panel and all its applets are gone.

Running 'killall -HUP unity-2d-panel' restores the panel in this case, meaning I guess that the process was still alive but somehow not responding.

I have not yet managed to pinpoint the exact conditions under which this bug happens. Generally it is when I already have one copy of NetBeans running and then run a second (testing) copy, though this does not reliably trigger the bug by any means. I use (Oracle) JDK 6u31 and 7u3, both in the 32-bit version.

Will attach a redacted copy of my ~/.xsession-errors from the current session. You can see several instances of "WARNING: Application 'unity-2d-panel.desktop' killed by signal" - any immediately preceding messages might be related to the crash.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: unity-2d-panel 4.12.0-0ubuntu1.1
ProcVersionSignature: Ubuntu 3.0.0-16.28-generic 3.0.17
Uname: Linux 3.0.0-16-generic x86_64
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Thu Mar 1 08:40:49 2012
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: unity-2d
UpgradeStatus: No upgrade log present (probably fresh install)

[Gerry Boland (gerboland)]

Hi,
thanks for the report. Is there a crash log of unity-2d-panel in your /var/crash directory by any chance?

The error message:
Window manager warning: Window 0x46003e6 (win1) sets an MWM hint indicating it isn't resizable, but sets min size 1 x 1 and max size 2147483647 x 2147483647; this doesn't make much sense.
is new to me, and possibly a symptom/cause.

Also, this might sound unusual, but have you tried clicking in the area that the panel was in? We have a bug report where the panel just becomes invisible, bug 894493. Just on the off-chance this is what's occurring.
Thanking you
-G

[Jesse Glick (jesse-glick)]

On 03/01/2012 01:10 PM, Gerry Boland wrote:
> Is there a crash log of unity-2d-panel in your /var/crash directory by any chance?

No, that dir is empty.

> The error message: Window manager warning: Window 0x46003e6 (win1) sets an MWM hint indicating it isn't resizable, but sets min size 1 x 1 and max size 2147483647 x
> 2147483647; this doesn't make much sense. is new to me, and possibly a symptom/cause.

Right, there may be some bug in AWT that tickles a panel bug. I have noticed for example that window sizing behaves erratically in Unity:

http://netbeans.org/bugzilla/show_bug.cgi?id=206077

> have you tried clicking in the area that the panel was in? We have a bug report where the panel just becomes invisible, bug 894493.

Not sure. The next time it crashes I will check that, including the workarounds mentioned there.

[Jesse Glick (jesse-glick)]

Just happened again and as in #894493 the panel is indeed still active but invisible; toggling /apps/metacity/general/compositing_manager fixes the symptom.

[dino99 (9d9)]

EOL have been reached, so no more maintenance. If that issue still exist, then report again using ubuntu-bug.