Error upgrading from Ubuntu 18.04 to 20.04

[Tom H]

On Thu, Jun 18, 2020 at 7:45 PM Paul Smith <paul at mad-scientist.net> wrote:
>
> This past weekend I decided to upgrade my system from 18.04 LTS to
> 20.04 LTS (yes, I know all about it not being officially offered
> until 18.04.1). I had upgraded my desktop from 19.10 to 20.04 with no
> problems.
>
> However, for the very first time in as long as I can remember I had a
> problem during the upgrade...
>
> If you're interested see:
> https://bugs.launchpad.net/ubuntu/+source/dpkg/+bug/1883980
>
> The thing is that my system is MOSTLY OK, but as I use it I can see
> there are problems. For example I discovered that the adwaita-icon-
> theme-full package was missing; installing that helped a lot. But,
> now I'm wondering what other packages should have been installed that
> weren't.
>
> Running dpkg --configure -a doesn't seem to do anything. Also running
> apt dist-upgrade doesn't seem to want to install much of anything
> interesting.
>
> Does anyone know where I can find a list of packages that are
> installed on a basic Ubuntu 20.04 LTS workstation system, that I can
> compare to what I have installed and look for missing things? Is such
> a thing published somewhere or do I have to install in a VM or
> somesuch?

What do
echo $PAGER
and
ll /etc/alternatives/pager
show?

Try
PAGER="less" pager="less" apt-get -f install
or
PAGER="/usr/bin/less" pager="/usr/bin/less" apt-get -f install