To avoid segfaults we need to hardcode the sip version.
We also need to write a Qt.conf as it was missing with PyQt 5.6 and QtWebEngine
can't find its resources.
While this makes things a little more complicated and means we'll need to use
`-r` to recreate tox environments, it has several advantages:
- Full support from requires.io (including PRs)
- Workaround for https://bitbucket.org/hpk42/tox/issues/332/ so we can update
virtualenv/pip
Things broke because of the virtualenv upgrade in requirements-tox.txt.
virtualenv bundles a "good" pip version (good: doesn't suffer
from #1486). However the virtualenv upgrade caused us to get a new
version which downloads a new pip. Setting VIRTUALENV_DOWNLOAD=no
prevents that from happening.
Having a Python script was a good idea back when we could do almost the
same steps on every CI configuration.
This turned out to grow into a complicated script, so it's easier to
split off things for Linux/OS X into a small shell script (and keep
Python for Windows, as I really don't want to use .bat/.ps).
This always caused problems and unneeded complexity in the past, and it
also increases Travis CI runtime.
We now require either a DISPLAY during tests or Xvfb being installed.
We used to use flake8-pep257 because docstrings claims no codes are ignorable
(which is wrong). However, that doesn't work with pydocstyle, so we had a
separate pydocstyle environment (and flake8-pep257 to check tests with relaxed
rules).
Now we only use flake8-docstrings + pydocstyle (which it switches to if it's
available, even though it still depends on pep257), and drop the pydocstyle tox
env.
As soon as flake8-docstrings is updated to drop the (unneeded) pep257
dependency, we can drop it as well.