What does this mean? `LIBGL_DEBUG=verbose glxinfo`?

Question

I type this LIBGL_DEBUG=verbose glxinfo because its supposed to help debug video problems and I get this http://pastebin.ubuntu.com/944871/

What does it all mean? Where can I learn more? What do you do with it?

Answer 1

The provided information is useful for users troubleshooting the OpenGL library and producing information that can help developers debugging the OpenGL library.

LIBGL_DEBUG
If defined debug information will be printed to stderr. If set to verbose additional information will be printed.

Source: http://dri.freedesktop.org/wiki/TestingAndDebugging

The command you are typing in: LIBGL_DEBUG=verbose glxinfo defines an environment variable LIBGL_DEBUG and sets it value to verbose. Then glxinfo starts and check certain environment variables and outputs more debug info in your case. After execution of program glxinfo this environment variable is set back to its prior value (most like it is undefined then).