Gentoo's version is 2.3.1, upstream's latest is 2.4.4. 2.4 release notes (plenty of new checks/features): http://pylint.pycqa.org/en/latest/whatsnew/2.4.html
Bumped in 287815fe9e64f5a6ec1be6072ddb5d20256eec63 without looking at existing bugs.