The issue probably stems from https://github.com/python/cpython/blob/138ccbb02216ca086047c3139857fb44f3dab1f9/Lib/logging/handlers.py#L828-L835. I doubt the logic of that comment, as in the non-unix-socket case, the error is raised if a connection cannot be established. Fixing the issue by re-considering that comment would have backward-incompatible implications and would violate the intention of the comment's author.