It looks like 2.16 increases the default version of black from 22.6 to 23.1.0, which crosses the year and thus means the formatting might change (https://black.readthedocs.io/en/stable/faq.html#how-stable-is-black-s-style). For instance, our repo was affected, as was the pants PR that made the change (https://github.com/pantsbuild/pants/pull/18431/files#diff-abcdaa33f726a45a24569b703bf8b95a9655d062fe87cb39d80653149f2d35d3). That PR increased a whole lot of default tool versions (isort, mypy, ...) that may break user code when upgrading 2.15 -> 2.16. Is this sort of tool version change considered a breaking change?

either way I think we should be careful to do such upgrades in a pants dev release so it’s not just part of a pants patch release. that said, there’s always the option to pin a tool version in order to make a tool upgrade != pants upgrade.

ah, yep, I see how it fits together now, thanks

It's certainly a tradeoff, with neither option being ideal. But in the end, the reason we provide default resolves for these tools is so users can get the latest and greatest without worrying about the how

Yeah, we should probably have a policy about this...