Bug#78371: conflict error does not check for replaces

[Goswin Brederlow <goswin.brederlow@student.uni-tuebingen.de>]

Josip Rodin <joy@cibalia.gkvk.hr> writes:

> On Sun, Dec 03, 2000 at 02:29:07AM +0100, Goswin Brederlow wrote:
> > > However, in this case that can't be done because APT has been told
> > > explicitely to install both packages. The bug here is that gpg-rsa is still
> > > available for installation -- it should be removed from the archive.
> > > I believe a bug to that effect has already been filed.
> > 
> > Yes, of cause, a different user input circumvents the problem and
> > removing the ols package also solves it (by giving an error that the
> > package is non existant).
> > 
> > 
> > But the situation can happen with many packages and the package will
> > allways be in potato.
> > 
> > It would be nice from apt-get to recognise that the extra package
> > given is just outdated and should be ignored, to tell the user this
> > with a warning and to go ahead and to go ahead not installing the old
> > but any remaining packages.
> 
> When you ask for an obsoleted package to be installed, you get something
> like this:
> 
> # apt-get install timezones
> Reading Package Lists... Done
> Building Dependency Tree... Done
> Package timezones has no available version, but exists in the database.
> This typically means that the package was mentioned in a dependency and
> never uploaded, has been obsoleted or is not available with the contents
> of sources.list
> However the following packages replace it:
>   libc6
> E: Package timezones has no installation candidate
> 
> So basically, APT can't guess which package replaces which, and especially
> when you list them _both_ on the command line.

"apt-get install timezones libc6" should tell me that timezone can't
be installed and go ahead instlling libc6 (after its usual yes/no
question).

Further, since libc6 replaces timezones, it should not give the full
error as above but just point out that libc6 replaces timezones and
that timezones therefore will be ignored.

The users request to install timezones will be fullfilled by the
second request to install libc6, so everything is as the user wants it
when apt-get install just libc6. Even in the case where multiple
packages replace  the requested package this will not be a problem,
since the user must have given one or more valid replacement (like the
libc6 above) for apt-get to give no error.

MfG
        Goswin