Hi everyone, TL;DR: is it time for us to update flake8 and break the world? Long version: Ussuri-supported Python runtimes will be python 3.6 and 3.7, which opens the marvelous world of f-strings to us. For those not familiar with f-strings, I recommend reading: https://realpython.com/python-f-strings/ In a recent project[1] I tried to use them, only to get pep8 job failures[2]. The old flake8 version we are using in hacking is exploding trying to parse f-strings, with a cryptic "AttributeError: 'FlakesChecker' object has no attribute 'JOINEDSTR'" error. Of course that was long-fixed in pyflakes (>=1.4.0) but that version is only used starting in flake8>=3.3.0, and hacking is capping flake8<2.7.0. We do cap those aggressively for a reason: bumping that cap triggers pep8 job failures everywhere as flake8 decides to pay attention to slightly different things, and we lose a lot of time collectively chasing down those syntax glitches everywhere. Which is why we haven't really bumped those since 2016... But proper support of f-strings might be a good reason to update? Thoughts? [1] https://review.opendev.org/#/c/695457/1 [2] https://zuul.opendev.org/t/openstack/build/bd97e5397b184176aac94251cc0a9220 -- Thierry Carrez (ttx)