AttributeError: module 'mistune' has no attribute 'BlockGrammar' in line 58 of m2r.py

[mcepl]

When packaging new version of mistune (2.0.0-rc1) is included into openSUSE/Factory, this package’s test suite starts failing:

[   32s] + /usr/bin/python3.6 setup.py build '--executable=/usr/bin/python3.6 -s'
[   32s] Traceback (most recent call last):
[   32s]   File "setup.py", line 14, in <module>
[   32s]     from m2r import parse_from_file
[   32s]   File "/home/abuild/rpmbuild/BUILD/m2r-0.2.1/m2r.py", line 58, in <module>
[   32s]     class RestBlockGrammar(mistune.BlockGrammar):
[   32s] AttributeError: module 'mistune' has no attribute 'BlockGrammar'
[   32s] error: Bad exit status from /var/tmp/rpm-tmp.G27V7P (%build)

Complete build log with all versions of packages used and steps taken.

[ahopkins]

I am getting this as well. Setting mistune<2.0.0 to fix the problem for now.

[crazyscientist]

This issue seems to be specific to Python 3.6.

With Python 3.8 m2r==0.2.1 and mistune==2.0.0 seem to work well together 🤔

[ahopkins]

This issue seems to be specific to Python 3.6.

My CI uses the latest 3.9 (via latest Sphinx).