UE4 demos: libGL error: No matching fbConfigs or visuals found

[ddurnev]

On Ubuntu 15.04 X64 with nvidia-349.12 and GTX 970 I try to run any of UE4 demos(atlantis or vehicle-game for example) and get the following when the library is preloaded:

libGL error: No matching fbConfigs or visuals found libGL error: failed to load driver: swrast X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 155 (GLX) Minor opcode of failed request: 3 (X_GLXCreateContext) Value in failed request: 0x0 Serial number of failed request: 99 Current serial number in output stream: 100

The same is true for the unigine-valley demo. Some other (simpler) openGL apps(for example glxgears) run OK and the result is logged to file.

[clbr]

Thanks for reporting. I'm not entirely sure this is libframetime's fault, and I can't test it myself. (No nvidia cards, UE4 demos are binary blobs, no spare computers that could run them.)

If you can reproduce with a cut-down open-source sample, that would be helpful.

[ddurnev]

Could you please advise how can I debug this X error to be sure that it's nvidia driver problem for example? What kind of open-source sample you mean? Any failing openGL app with open sources will do?

[clbr]

If you install debug packages, you should be able to track what kind of visual the demo is asking for in gdb (set breakpoints to all the glx visual functions). Then you match those against your glxinfo output, to see if that visual really does not exist.

Yes, any open-source app will do, but a cut-down sample would be better, so I don't have to download gigabytes of data to run it.

[ddurnev]

Maybe I could track the visual id in X request just by examining the ltrace of libGL calls even without source or debug info?