I have two machines running Fedora 21. If I ,or the Nvidia Linux Graphics Debugger, launch any OpenGL program (including glxinfo) with libNvidia_gfx_debugger.so preloaded on either machine, then it will crash in a glx function.
On a machine with an Nvidia GeForce GTX 650 Ti GPU, using the proprietary Nvidia drivers version 352.30, then it will jump to address 0 in any use of glXMakeCurrent after producing this output:
NGD: Starting GTI initialization... NGD: Graphics interception initialized
On a machine with an AMD R9 GPU, using fglrx 15.20.1046, then it will exit with status code 0377 from glXChooseVisual after producing this output:
NGD: Starting GTI initialization... Found libGL.so.1 but it does not appear to be an Nvidia driver library. NGD: Fatal Error: Cannot find any system GLX library.
If I connect to a host running Ubuntu 14.04, I don’t get these crashes.