The Information provided on Community Help may helpful for dealing with partial upgrade:
During the past few Ubuntu development cycles, we've been flooded with
threads asking for assistance related to issues caused by careless
usage of the "Partial Upgrade" feature of Update Manager, which hinted
to a poor understanding of package management and the way updates
happen in the development branch.
In an effort to help with this situation, this document aims to
clarify what a Partial Upgrade is, and why, in most cases, you'll want
to avoid it.