Re: Should we allow packages to depend on packages with lower priority values?
Marc Haber wrote:
> Santiago Vila <sanvila@unex.es> wrote:
> >On Mon, 8 Dec 2003, Marc Haber wrote:
> >> Policy 2.5 says that packages must not depend on packages with lower
> >> priority values. From what I tried to research, that rule is meant to
> >> allow CD builders to build "Debian foo standard" CDs containing
> >> required, important and standard packages, guaranteed that all
> >> dependencies are satisfied just from choosing from the Priority.
> >
> >Not only that, combined with the rule saying "packages which conflicts
> >with optional or higher should be extra", people should be able to
> >forget completely about extra packages when choosing packages without
> >having unmet dependencies.
>
> Why should they be able to forget about extra packages. I don't see
> any place where this matters, except CD creation.
Because the fact that there should not be conflicts among optional or
higher packages often forces Debian to choose which one, among a set
of packages which conflict at each other, should be the optional or
the standard one and put all the others in extra.
By choosing only among optional or higher packages (i.e. forgetting
about extra), a novice user which want to avoid problems will:
a) find at least some "recommended" package for every task for which
there are several incompatible packages.
b) not need to bother about resolving conflicts at all.
This is not about CD creation at all.
> >> Now let's look at a system where the local administrator has decided
> >> to use B instead of A. Since E and F are Priority: important, dselect
> >> happily proceeds to install E and F on the system, even if they are
> >> not needed since the system in question uses B instead of A.
> >
> >So you want postfix but not the dependencies for exim?
>
> This is just an example.
>
> >Just tell dselect to uninstall E and F. Where is the problem?
>
> Manual intervention is necessary here. Most people will see this as a
> bad bug in the E and F packages.
Most people would see that as a bug if dselect didn't honor your
request of uninstalling E and F, but dselect does honor such requests.
> >You will only have to do this once and dselect will remember that you
> >don't want E and F installed (unless they are required later by another
> >package).
>
> Everybody using B will have to do this once.
They don't really *have* to do it. Packages E and F will typically be
libraries, which do nothing if no package uses them. Having them
installed is completely harmless.
They can remove E and F if they don't want to have them installed, but
this has only to be made *once*.
I don't understand why you make such a big problem from uninstalling a
package which you don't want. Why don't you just propose to downgrade
all important and standard packages to optional, then, since
uninstalling those which you don't want is such a big problem?
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