https://irrd.readthedocs.io/en/stable/releases/4.3.0/
4.3.0 was initially released on June 6th, 2023, but was yanked due to a packaging error on June 9th, leading to the release of IRRd 4.3.0.post1. The main visible issue from the error was that the documentation of 4.4 was published as 4.3.0. If you had previously installed 4.3.0 through PyPI/pip, you can keep running on that version, or update to 4.3.0.post1 without needing restarts or migrations, as the 4.3.0 and 4.3.0post1 PyPI packages have identical code.