Bug report

Bug description:

This is an intentional change done in #121089, following #121027. That PR disregarded PEP-387 and breaks compatibility with less than a version warning (less than because the FutureWarning that was added was late in the python 3.13 release cycle)

I don't know if there is much more to add to this bug report - this change should not have been done without a proper deprecation period and IMO a proper discussion outside of two github issues. It should be reverted for 3.14 and a deprecation warning be added instead, with the final change, if being done at all, the earliest in 3.16.

It also already caused other issues, at least #125316. The reason I noticed this is because it broke actual tests on a project I am maintainer on: lark-parser/lark#1480

CPython versions tested on:

3.14

Operating systems tested on:

Windows