[X2Go-Dev] Bug#1390: Bug#1390: x2go server openGL errors are printed in high volume at less than a millisecond time-scale to the log file

[Ulrich Sibiller]

On Tue, May 28, 2019 at 10:58 PM Piotr Balwierz <balwierz at gmail.com> wrote:
>
> Package: x2goserver
> Version: 4.1.0.3-4
>
> Debian Buster
>
> OpenGL error messages from gl_surface_qt.cpp (qtwebengine likely) are printed on 0.01 of a millisecond time scale (i.e. 10^5 messages per second) to a log file.
> Currently my log file is 16 TB in size. This is a error log file from a single session, because https://bugs.x2go.org/cgi-bin/bugreport.cgi?bug=923 is resolved.
>
> $ls -la ~/.xsession-x2go*
> -rw------- 1 user users 17557623775232 May  2 23:40 .xsession-x2go-mamut-errors
> -rw------- 1 user users          38176 Jun 18  2018 .xsession-x2go-mamut-errors.old
>
>
> The content of the file is extremely boring:
> [...]
> [51916:52005:0422/215628.936583:ERROR:gl_surface_qt.cpp(296)] eglCreatePbufferSurface failed and surfaceless context not available
> [51916:52005:0422/215628.936597:ERROR:gl_surface_qt.cpp(303)] Requested OpenGL implementation is not supported. Implementation: 0
> [51916:52005:0422/215628.936612:ERROR:gl_surface_qt.cpp(296)] eglCreatePbufferSurface failed and surfaceless context not available
> [51916:52005:0422/215628.936627:ERROR:gl_surface_qt.cpp(303)] Requested OpenGL implementation is not supported. Implementation: 0
> [51916:52005:0422/215628.936642:ERROR:gl_surface_qt.cpp(296)] eglCreatePbufferSurface failed and surfaceless context not available
> [51916:52005:0422/215628.936656:ERROR:gl_surface_qt.cpp(303)] Requested OpenGL implementation is not supported. Implementation: 0
> [...]

The .xsession-errors file contains stderr of your applications run
within the session. Your application tells you via stderr it is not
supporting the OpenGL implementation X2go offers. Bad Luck. Do these
workarounds help?:
- run <your app> 2>/dev/null from an xterm and see if that helps.
- try running you application without OpenGL support.
- try if this workaround can help you:
https://wiki.x2go.org/doku.php/wiki:development:glx-xlib-workaround?s[]=libgl

> Expected behaviour: Too quickly appearing messages from the same process should not end up in the log file. systemd-journald if I am correct has such a feature.
> I am not reporting it to qtwebengine or Rstudio right now. Will do if encouraged in your comments.

Well, it is your application producing errors at a high frequency. It
shoudl be fixed there. (BTW: It would happen in a normal X session,
too.)

Uli