Please see :ref:`the installation docs <release-lines>` which have an explicit section about this topic.
In an ideal world, the developers would love to support every possible target system. Unfortunately, volunteer development time and access to non-mainstream platforms are limited, meaning that we can only fully support standard OpenSSH implementations such as those found on the average Linux distribution (as well as on Mac OS X and *BSD.)
Because of this, we typically close bug reports for nonstandard SSH implementations or host systems.
However, closed does not imply locked - affected users can still post comments on such tickets - and we will always consider actual patch submissions for these issues, provided they can get +1s from similarly affected users and are proven to not break existing functionality.
Make sure you explicitly .close() your connection objects (usually
SSHClient) if you're having any sort of hang/freeze at shutdown time!
Doing so isn't strictly necessary 100% of the time, but it is almost always the right solution if you run into the various corner cases that cause race conditions, etc.