follow-up (and problems) about: recommendation for all-in-one printer?

[Colin Watson]

On Fri, Nov 06, 2020 at 02:45:51PM +0100, Liam Proven wrote:
> `apt upgrade` is the equivalent of `apt-get upgrade`. It installs new
> versions of existing packages but it will not add packages or
> additional dependencies.

Not quite.  "apt-get upgrade" will never add packages (it will instead
hold upgrades if there are new dependencies that require adding
packages), while "apt upgrade" will add packages if necessary to satisfy
new dependencies.

Neither will ever *remove* packages, though.

My understanding is that the reason for this change in semantics from
"apt-get upgrade" to "apt upgrade" is that needing to add packages is
quite common across things like library ABI changes and is generally
relatively harmless, so the behaviour of "apt-get upgrade" was a bit too
annoyingly conservative in practice.

> `apt full-upgrade` is the equivalent of the old `apt-get
> dist-upgrade`. If a new version needs a new dependency or library or
> something, it will do it.

As does "apt upgrade" (but not "apt-get upgrade").  The difference
between "apt upgrade" and "apt full-upgrade" is that the former will
hold upgrades if there are new conflicts that require removing packages,
while the latter will remove packages if necessary to satisfy new
conflicts.

(I agree with the recommendation to use "apt full-upgrade" in most
cases.)

-- 
Colin Watson (he/him)                              [cjwatson at ubuntu.com]