Python 2.4.0 onwards relies on Libcouchbase 2.9.0+, if you try to install Python 2.4.0 with an earlier Libcouchbase you get warnings about crypto methods:
These errors are pretty cryptic unless you're in the know about what features were added to which SDK when.
It would be a much better experience for everyone if any time we had to bump the minimum libcouchbase dependency we could have some installation-level check saying something like:
Libcouchbase 2.9.0 required, version 2.8.2 found. Please update libcouchbase to a later version before installing this version of the Python SDK.
This is a clear error message for the user, with clear instructions for how to resolve their issue.
As an aside https://developer.couchbase.com/server/other-products/release-notes-archives/python-sdk does not cover the need for a minimum version of Libcouchbase.