Interrupted release upgrade, how to sort out left-over old packages?

[Tom H]

On Wed, May 18, 2016 at 2:25 PM, Chris Green <cl at isbd.net> wrote:
>
> I think I know now the cause of my 'left-over' PHP5 packages in a
> 16.04 installation. (See previous thread)
>
> The system in question got interrupted (the cat walked across the
> keyboard!) while doing a do-release-upgrade. I restarted it and after
> a couple of 'apt-get update' and an 'apt-get dist-upgrade' it seemed
> to have sorted itself out and have 16.04 properly installed.
>
> However, obviously not all the packages that should have been upgraded
> were upgraded, hence my left-over PHP5 packages.
>
> I've sorted out the PHP5 ones now but I suspect there may be other
> left-over packages from 15.10 that haven't been updated. Is there any
> way I can check and update them?

The simplest would be to install aptitude (if it isn't installed) and run

## are installed but are no longer installable
aptitude search ~o

## were installed as dependencies but are no longer required
aptitude search ~g

## are uninstalled but still have configuration files on-disk
aptitude search ~c