• 6.6.0 (2018-02-12)
• https://github.com/getsentry/raven-python/releases

QGIS is provided with a old version of contextlib. I had to manually update the Raven package. If you update Raven, you might need to check this change.

In raven/base.py, replace:

if sys.version_info >= (3, 2):
    import contextlib
else:
    import contextlib2 as contextlib

by:

try:
    import contextlib
except ImportError:
    import contextlib2 as contextlib

I could remove 'raven/contrib' folder to make the library smaller.