Subject: Re: [X2Go-Dev] Black window with KDE5 plasma

From: Klaus Fuerstberger <[email-masked]>
Date: Fri, 1 Sep 2017 12:42:41 +0200

Am 01.09.2017 um 07:18 schrieb Mihai Moldovan:
> On 08/28/2017 03:46 PM, Klaus Fuerstberger wrote:
>> I tested an KDE Neon LTS 5.8 (based on Ubuntu xenial) and KDE Neon 5.9
>> (based on Ubuntu zesty) on my system. With both distributions, nouveau
>> and mesa glx is running fine. Also connecting with x2go to an x2goserver
>> installed is no problem.
>> After compiling and installing the mentioned latest NVIDIA driver, x2go
>> fails again to launch KDE plasma.
> 
> This is likely the cause because the nVidia driver installs its own libGL version.
> 
> This is fine as long you only ever use the machine locally, but fails badly in
> use cases such as X2Go.
> 
> Typically it might be possible to ignore the directory in which the package
> installs this special libGL version and thus making sure that the MESA-gl
> version is being used. Not a trivial task to do from X2Go's viewpoint, since the
> libGL directory is hardcoded within the system's ld.so.conf file.

The nvidia driver installer removes the conflicting mesa drivers and
especially /usr/lib/x86_64-linux-gnu/libGL.so.1.2.0

If I backup this library bevor installing the nvidia driver and change
one symbolic link pointing to the systems library then x2go works fine.

# cd /usr/lib/x86_64-linux-gnu
# ls -l libGL.so
lrwxrwxrwx 1 root root 10 Sep  1 10:46 libGL.so -> libGL.so.1

The nvidia one
#ls -l libGL.so.1
lrwxrwxrwx 1 root root 14 Sep  1 11:09 libGL.so.1 -> libGL.so.1.0.0

rm libGL.so.1
# The original library of the system
ln -s libGL.so.1.2.0 libGL.so.1

Of course this workaround does not function, when started with the x2go
Xsession, because the user has no write permissions in
/usr/lib/x86_64-linux-gnu.

I wonder why x2go worked bevor with KDE4 and the nvidia drivers.

Klaus