Black screen on Kubuntu 22 LXD container

[Michael Eager]

On 8/13/22 04:00, René J.V. Bertin wrote:
> On Saturday August 13 2022 02:41:17 Duncan wrote:
>> Michael Eager posted on Wed, 10 Aug 2022 06:40:46 -0700 as excerpted:
>>
>>> I'm running Kubuntu 22.04 in an LXD container.
>>>
>>> When I connect using x2go, KDE starts up (I see the splash screen) but
>>> then the screen goes black with a cursor. After a short time, the lock
>>> screen is shown, with password field, so I think that x2go is working.
>>> When I log in, the screen goes black.  There is a cursor, but neither
>>> left nor right clicks have any effect.
> 
> 
> I suppose this means your session and x2go run on 2 different machines

Yes.

> To me it sounds like KDE could be trying to use compositing on a (remote) display channel that doesn't support this. Normally it should turn off the feature if it detects that it isn't supported but maybe there's a miscommunication going on here. One possible way to determine this is to open a terminal emulator or even to ssh in, and replace the KWin window manager with a simple WM that supports the --replace argument (e.g. xfwm4, which can be started with --compositor=off to ensure it won't use this feature).
> If that gives you more than just a black screen you can then use the GUI to disable the compositor in KWin, or experiment with different backends. The older KWin version I use, for instance, can use (emulate?) compositing with the legacy XRender backend, which happens to work better with my GPU and supports the few GUI effects I find useful. (NB: you can switch back to KWin with `kwin_x11 --replace &`)

I'm not sure how to follow your suggestion.  What should I change?

> Are there other ways you can connect to the container, VNC for instance?

With VNC, I get an unresponsive gray screen, but otherwise the same.