The last time stickler had a look at our PRs is 8 days ago (#2415) : https://stickler-ci.com/repositories/26661-pydata-xarray

It looks like their bot is broken: https://github.com/stickler-ci

This is not very trustworthy - we could consider switching to https://pep8speaks.com/ maybe