`glxgears` doesn't work for me as X-Fowarding test

[dstansby]

On https://www.rc.ucl.ac.uk/docs/Wiki_Export/X-Forwarding/#checking-your-setup there's a suggestion to use glxgears to check that X-forwarding is working. glxgears doesn't work for me on a macOS host:

$ glxgears
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:  149 (GLX)
  Minor opcode of failed request:  3 (X_GLXCreateContext)
  Value in failed request:  0x0
  Serial number of failed request:  36
  Current serial number in output stream:  38

and it took me a little while to work out that X-forwarding was working fine, but it was glxgears that wasn't. Checking by launching xterm worked fine though, so maybe worth removing the suggstion to check using glxgears?

[heatherkellyucl]

@dstansby You're looking at an old page (anything in Wiki_Export is historical). See https://www.rc.ucl.ac.uk/docs/howto/#how-do-i-run-a-graphical-program which uses nedit as the example.

We do need to finish deleting/retrieving anything useful from the old pages.

[dstansby]

Woops, thanks for letting me know I was in the wrong place!

[ikirker]

@dstansby This error message also indicates that while X-Forwarding is working, GLX ("the 3D remote rendering capability") is not working for you. Which is what that program is intended to test.

XQuartz by default disables GLX indirect rendering. Assuming you're using XQuartz, you can change that by entering, on the macOS machine:

defaults write org.xquartz.X11 enable_iglx -bool true

and then quitting XQuartz and making it re-open.

I'll find somewhere to add this to the docs at some point.