Troubleshooting

tox: InvocationError without further information

It might happen that your tox run finishes abruptly without any useful information, e.g.:

ERROR: InvocationError:
'/path/to/project/.tox/py36/bin/python setup.py test --addopts --doctest-modules'
___ summary _____
ERROR: py36: commands failed

pytest-qt needs a DISPLAY to run, otherwise Qt calls abort() and the process crashes immediately.

One solution is to use the pytest-xvfb plugin which takes care of the grifty details automatically, starting up a virtual framebuffer service, initializing variables, etc. This is the recommended solution if you are running in CI servers without a GUI, for example in Travis or CircleCI.

Alternatively, tox users may edit tox.ini to allow the relevant variables to be passed to the underlying pytest invocation:

[testenv]
passenv = DISPLAY XAUTHORITY

Note that this solution will only work in boxes with a GUI.

More details can be found in issue #170.