Comment 4 for bug 714784

It occurred to me that glxinfo is from a package in universe and I was able to recreate the crash using the following steps:

8:28:59 - flash:[~/Documents/subtitles] sudo chmod -x '/usr/bin/glxinfo'
[sudo] password for bdmurray:
8:29:10 - flash:[~/Documents/subtitles] ubuntu-bug xorg
ERROR: hook /usr/share/apport/package-hooks//source_xorg.py crashed:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/apport/report.py", line 637, in add_hooks_info
    symb['add_info'](self, ui)
  File "/usr/share/apport/package-hooks//source_xorg.py", line 450, in add_info
    attach_3d_info(report, ui)
  File "/usr/share/apport/package-hooks//source_xorg.py", line 332, in attach_3d_info
    report['glxinfo'] = command_output_quiet(['glxinfo'])
  File "/usr/lib/python2.7/dist-packages/problem_report.py", line 510, in __setitem__
    and (hasattr(v[0], 'isalnum') or hasattr(v[0], 'read'))))
AssertionError

The existence of glxinfo should be tested before trying to run it.