xfwm4 crashing after Xubuntu 19.10 upgrade

[C. Jeffery Small]

After recovering from a failed upgrade from Xubuntu 19.04 to 19.10, I'm left with a system where the xfwm4 window manager is constantly crashing. I get a desktop on my primary screen :0.0 but there is neither a xfce4-panel nor a window manager. With great difficulty I can start apps, but without the window manager, there is no way to move, resize or close them. Overlapping or hidden windows remain as such. You cannot use right-click or pull-down menus in most apps.

Every attempt to start xfwm4 results in a crash with a crash file in /var/crash.

This message in kern.log:

Jan 12 20:22:38 dymaxion kernel: [ 54.589712] traps:
    xfwm4[5044] trap int3 ip:7fc4d1afb8e5 sp:7fff265927e0 error:0
    in libglib-2.0.so.0.6200.1[7fc4d1ac0000+83000]

indicates that the problem is an interaction with libglib-2.0.so.0.6200.1. Both xfwm4 and the libglib package that provides the above library have been reinstalled.

Any suggestions would be greatly appreciated as I'm pretty much dead in the water at the moment.

PS: This bug was also reported to the XFCE group here:

https://bugzilla.xfce.org/show_bug.cgi?id=16374

[C. Jeffery Small (loyhz2ay-jeff-h670zbts)]

Following up:

The xfwm4 crashing problem has to do with defining more than one independent screen in the /etc/X11/xorg.conf file. This is a problem observed by at least one other person. By commenting out the second screen in the ServerLayout section, it was possible to get the system running using the Nvidia drivers. Apparently this bug was also causing audio output to fail for unknown reasons. After the graphics problem was rectified, proper sound operation was once again also restored.

I hope this information helps others experiencing this problem. Follow this issue at:

https://bugzilla.xfce.org/show_bug.cgi?id=15852

[JXT (jtipton-x-deactivatedaccount)]

Sadly this seems to be what I'm dealing with. Everything newer than 18.04 breaks once you have a second XScreen/GPU. https://bugs.launchpad.net/ubuntu/+source/xfwm4/+bug/1942477

Seems to be bigger than the DE tough because I've tried a few different distros (not just debian) and various DE's all do roughly the same thing. I originally reported as a XOrg/Kernel change is causing this down the line. Still waiting to hear/see anything about how accurate that theory is though. The fact your bug has been open over a year and the issue persists even in 21.04 makes me think I'm about to get screwed out of a GPU and several screens.

[C. Jeffery Small (loyhz2ay-jeff-h670zbts)]

Yes, after 18.04, it was no longer possible to run two independent desktop sessions, even if you have a single GPU supporting multiple screens. It boggles my mind why this incredibly useful capability was allowed to just die. You can still gang the two screens together with the panel running on one screen and the window manager running across both, but you cannot control them independently; i.e., if you switch desktops both screens change rather than just the one you would like.

[JXT (jtipton-x-deactivatedaccount)]

WTF site just ate my comments and inserted a copy of your original post lol crack head az$ site.

So I just went to try Wayland...and didn't! I grabbed Kubuntu (despite really dislikeing KDE) just to try and that running XOrg works! Installer failed a bunch of times but after a lot jerry rigging and fixing once I got in it actually works. I've tried other Debian Ubuntu 21.04 based releases (and a few current Arch) and none worked but KUbuntu did/does! Now the question...WHY!?

Spoke a tad too soon. It works in that it doesn't lock up and crash like the other flavors do once another XScreen is added but tons of other issues. Really scrambling here with how to move forward without losing serious money in hardware and workflow.

[JXT (jtipton-x-deactivatedaccount)]

Sadly this will *never* be fixed unless XFCE dumps GTK as this is caused by GTK. Since GTK 3.something GTK ignores all XScreens and assumes just one causing the problem.

Current KDE works for Multi-XScreen/GPU but has some idiotic maximize behavior. The only thing I've found really functional is ctwm but then you have to roll your own to have normal Desktop functionality.

[JXT (jtipton-x-deactivatedaccount)]

Glad to see this is "new" *sarcasm*. I've moved to ctwm. There isn't much refuge left unless you conform to single GPU/XScreen Wayland/randr setups. Even Evolution relies on GTK which makes ancient "pure" xorg tools or KDE the only choice.