Xephyr not running on Nvidia drivers on Autopilot plugin for Qt Creator

[Carla Sella]

In the new Autopilot plugin for Qt Creator, Xephyr does not run on Nvidia drivers.
I get this output:

Starting /usr/bin/autopilot3-sandbox-run...
I: Running tests ubuntu_clock_app.tests.test_clock.TestClock.test_add_city_by_searching_must_add_world_city
I: Starting X Server: /usr/bin/Xephyr :5 -ac -br -noreset -screen 320x600x24
I: Starting autopilot
sudo: no tty present and no askpass program specified
Loading tests from: /home/letozaf/autopilot-tests/ubuntu-clock-app/tests/autopilot

Tests running...
Xlib.xauth: warning, no xauthority details available
<class 'Xlib.protocol.request.QueryExtension'>
Xlib: extension "GLX" missing on display ":5.0".
sudo: no tty present and no askpass program specified
======================================================================
ERROR: ubuntu_clock_app.tests.test_clock.TestClock.test_add_city_by_searching_must_add_world_city
----------------------------------------------------------------------
Binary content:
  FailedTestScreenshot (image/png)
Empty attachments:
  process-stdout (/usr/lib/x86_64-linux-gnu/qt5/bin/qmlscene)

/var/log/syslog: {{{Jul 12 11:28:30 letozaf-PC kernel: [ 719.475662] input: autopilot-finger as /devices/virtual/input/input13}}}
process-return-code (/usr/lib/x86_64-linux-gnu/qt5/bin/qmlscene): {{{-6}}}
process-stderr (/usr/lib/x86_64-linux-gnu/qt5/bin/qmlscene): {{{
Xlib: extension "GLX" missing on display ":5.0".
Xlib: extension "GLX" missing on display ":5.0".
Xlib: extension "GLX" missing on display ":5.0".
Xlib: extension "GLX" missing on display ":5.0".
Xlib: extension "GLX" missing on display ":5.0".
Xlib: extension "GLX" missing on display ":5.0".
Could not initialize GLX
}}}

test-log: {{{
11:28:31.041 INFO logging:45 - TestClock: launch_test_local. Arguments (). Keyword arguments: {}.
11:28:31.041 WARNING base:52 - This function is deprecated. Use get_toolkit_launcher_command() instead.
11:28:31.097 INFO _launcher:373 - Attempting to launch application '/usr/lib/x86_64-linux-gnu/qt5/bin/qmlscene' with arguments '/home/letozaf/autopilot-tests/ubuntu-clock-app/app/ubuntu-clock-app.qml -I /home/letozaf/autopilot-tests/build-ubuntu-clock-app-Desktop-Default/backend' as a normal process
11:28:31.103 INFO _launcher:431 - Launching process: ['/usr/lib/x86_64-linux-gnu/qt5/bin/qmlscene', '-testability', '/home/letozaf/autopilot-tests/ubuntu-clock-app/app/ubuntu-clock-app.qml', '-I', '/home/letozaf/autopilot-tests/build-ubuntu-clock-app-Desktop-Default/backend']
11:28:32.234 INFO _launcher:544 - waiting for process to exit.
11:28:32.234 INFO _launcher:567 - Killing process 20108
11:28:32.235 INFO _launcher:570 - Appears process has already exited.
}}}

Traceback (most recent call last):
  File "/home/letozaf/autopilot-tests/ubuntu-clock-app/tests/autopilot/ubuntu_clock_app/tests/test_clock.py", line 40, in setUp
    super(TestClock, self).setUp()
  File "/home/letozaf/autopilot-tests/ubuntu-clock-app/tests/autopilot/ubuntu_clock_app/tests/__init__.py", line 80, in setUp
    self.app = ubuntu_clock_app.ClockApp(self.launcher(), self.test_type)
  File "/usr/lib/python3/dist-packages/autopilot/logging.py", line 46, in inner
    return f(instance, *args, **kwargs)
  File "/home/letozaf/autopilot-tests/ubuntu-clock-app/tests/autopilot/ubuntu_clock_app/tests/__init__.py", line 101, in launch_test_local
    emulator_base=ubuntuuitoolkit.UbuntuUIToolkitCustomProxyObjectBase)
  File "/usr/lib/python3/dist-packages/autopilot/testcase.py", line 279, in launch_test_application
    return launcher.launch(application, arguments, **launch_args)
  File "/usr/lib/python3/dist-packages/autopilot/application/_launcher.py", line 384, in launch
    pid=process.pid
  File "/usr/lib/python3/dist-packages/autopilot/introspection/_search.py", line 171, in get_proxy_object_for_existing_process
    process
  File "/usr/lib/python3/dist-packages/autopilot/introspection/_search.py", line 312, in _find_matching_connections
    _raise_if_process_has_exited(process)
  File "/usr/lib/python3/dist-packages/autopilot/introspection/_search.py", line 334, in _raise_if_process_has_exited
    % return_code
autopilot.exceptions.ProcessSearchError: Process exited with exit code: -6

Ran 1 test in 1.795s
FAILED (failures=1)
I: autopilot tests done
/usr/bin/autopilot3-sandbox-run exited with code 1

I am running Wily and this is my hardware:
https://gist.github.com/anonymous/3203c7c5a43a509c0f22

[Nicholas Skaggs (nskaggs)]

This occurs on all non-free drivers. Not something we can fix with the plugin, so I suppose we'll need to support Xfvb as a fallback.

[Nicholas Skaggs (nskaggs)]

If we can detect this automagically, we should revert these users to using Xfvb instead. We could note this in the issues pane if desired.

To run under Xfvb instead, change

autopilot3-sandboxrun - X

to

autopilot3-sandboxrun