napari: Segfault with Dask and OpenCV

🐛 Bug

To Reproduce

Steps to reproduce the behavior:

import dask, cv2, napari
from skimage import data
with napari.gui_qt():
    _ = napari.view_image(data.astronaut())

• This happens in both the interactive prompt and by running the script from the command line.
• Not importing dask resolves the issue
  • I need dask, though 😕/

Expected behavior

The image should be displayed

Environment

napari: 0.2.12
Platform: Darwin-19.4.0-x86_64-i386-64bit
Python: 3.6.8 (v3.6.8:3c6b436a57, Dec 24 2018, 02:04:31) [GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.57)]
Qt: 5.13.2
PySide2: 5.13.2
VisPy: 0.6.4
NumPy: 1.18.1
SciPy: 1.4.1
scikit-image: 0.16.2
Dask: 2.11.0

GL version: 2.1 INTEL-14.5.17
MAX_TEXTURE_SIZE: 16384

Additional context

When I run my script, this output always occurs when importing napari and cv2 together:

objc[2836]: Class QMacAutoReleasePoolTracker is implemented in both /Users/suman/Library/Caches/pypoetry/virtualenvs/pymana-zNasaWCC-py3.6/lib/python3.6/site-packages/cv2/.dylibs/QtCore (0x121ec3700) and /Users/suman/Library/Caches/pypoetry/virtualenvs/pymana-zNasaWCC-py3.6/lib/python3.6/site-packages/PySide2/Qt/lib/QtCore.framework/Versions/5/QtCore (0x125b59700). One of the two will be used. Which one is undefined.
objc[2836]: Class QT_ROOT_LEVEL_POOL__THESE_OBJECTS_WILL_BE_RELEASED_WHEN_QAPP_GOES_OUT_OF_SCOPE is implemented in both /Users/suman/Library/Caches/pypoetry/virtualenvs/pymana-zNasaWCC-py3.6/lib/python3.6/site-packages/cv2/.dylibs/QtCore (0x121ec3778) and /Users/suman/Library/Caches/pypoetry/virtualenvs/pymana-zNasaWCC-py3.6/lib/python3.6/site-packages/PySide2/Qt/lib/QtCore.framework/Versions/5/QtCore (0x125b59778). One of the two will be used. Which one is undefined.
objc[2836]: Class KeyValueObserver is implemented in both /Users/suman/Library/Caches/pypoetry/virtualenvs/pymana-zNasaWCC-py3.6/lib/python3.6/site-packages/cv2/.dylibs/QtCore (0x121ec37a0) and /Users/suman/Library/Caches/pypoetry/virtualenvs/pymana-zNasaWCC-py3.6/lib/python3.6/site-packages/PySide2/Qt/lib/QtCore.framework/Versions/5/QtCore (0x125b597a0). One of the two will be used. Which one is undefined.
objc[2836]: Class RunLoopModeTracker is implemented in both /Users/suman/Library/Caches/pypoetry/virtualenvs/pymana-zNasaWCC-py3.6/lib/python3.6/site-packages/cv2/.dylibs/QtCore (0x121ec37f0) and /Users/suman/Library/Caches/pypoetry/virtualenvs/pymana-zNasaWCC-py3.6/lib/python3.6/site-packages/PySide2/Qt/lib/QtCore.framework/Versions/5/QtCore (0x125b597f0). One of the two will be used. Which one is undefined.

Interestingly, importing dask doesn’t cause any warning.