Warning users about dropped packages during upgrade
it'd be nice if apk warned users if a package they've installed isn't available in the repositories anymore because it has been removed (e.g. moved to unmaintained, deleted because deprecated like py2-* things). Orphaned packages are bound to cause problems to the user at some point, e.g. when they can't upgrade their system anymore because of a soname bump in some library. We had some users having old long removed py2-* packages installed that needed libffi.so.6 but we only had libffi.so.7 available after an upgrade. As such users were unable to upgrade before they removed the unsupported package.