Subject: Re: Bug#594116: diff dummy package auto-reinstall

From: David Kalnischkies <[email-masked]>
Date: Tue, 24 Aug 2010 13:34:52 +0200

forcemerge 216768 594116
thanks

Oldy but goldy. Make sure to read the merges for full enjoyment
as i will only give short comments here as the full details are
already said in other mails…

2010/8/23 Santiago Vila <[email-masked]>:
> On Mon, 23 Aug 2010, Rodolfo Garcia wrote:
>> When I remove the package (dummy) I do not have any problem. But in
>> the next apt-get dist-upgrade it will be installed. I tryed to find
>> why, but I cannot find any reason.
>
> Moreover, "apt-get dist-upgrade" insist on installing essential
> packages *even if they are not essential anymore*.

The question is: How should APT know that squeeze is the
successor of lenny? Also, diffutils doesn't say that it is a complete
and fullfeatured replacement for diff - as it more or less impossible
to express it in a sane way with dependencies. So if a package
previously depends (implicit) on a feature of diff, does diffutils really
provides the very same feature (even Provides doesn't say that it
is 100% backward compatible) …

> There may be legitimate reasons why apt should install essential
> packages, but I wish it would be a little bit smarter in cases like
> this one and realize that diff is not essential anymore.

The problem is: All packages on your system maybe depend on
diff, so just because it is dropped in the next release doesn't mean
that your system is fully upgraded to the next release and therefore
no package depending on old diff is left -- if your system would be
fully uptodate, why would have the old sources?

Getting all essentials is the same in green: New essentials need
to be installed in a dist-upgrade even if no package depends on
them explicit as (new) packages could depend on it implicit…

> As there is nothing in diffutils which may be made to fix this
> behaviour, and I believe there is still room in apt for an
> improvement, I reassign this to apt.

Last not least: APT recently got a well hidden option for all those
people who really think they need to care about it and want to
hunt down essential packages in the future by hand instead of
automatic…

/me still thinks it is funny that people want to remove obsolete
packages but not obsolete sources.list entries…

Best regards

David Kalnischkies