Re: provides and dependencies

[Sven <luther@dpt-info.u-strasbg.fr>]

On Fri, Dec 21, 2001 at 02:00:37PM +0100, Jérôme Marant wrote:
> Sven <luther@dpt-info.u-strasbg.fr> writes:
> 
> > Hello, ...
> 
> Hi,
> 
> > I have a package C, which i wanted to make depend on B only, but which should
> > also work when A is installed, since A provides B.
> > 
> > But this does not work, when A is installed C refuses to install.
> 
>   What does dpkg tell when you try to install C?

luther@iliana:~/debian/lablgl$ sudo dpkg -i lablgl-runtime_0.97-1.1_i386.deb
(Lecture de la base de données ... 79532 fichiers et répertoires déjà
installés.)
Dépaquetage de lablgl-runtime (à partir de lablgl-runtime_0.97-1.1_i386.deb)
...
dpkg: des problèmes de dépendances empêchent la configuration de
lablgl-runtime:
 lablgl-runtime dépend de ocaml-base (>= 3.04); cependant :
  Paquet ocaml-base n'est pas installé.
 lablgl-runtime dépend de ocaml-base (<< 3.05); cependant :
  Paquet ocaml-base n'est pas installé.
dpkg: erreur de traitement de lablgl-runtime (--install):
 problèmes de dépendances - laissé non configuré
Des erreurs ont été rencontrées pendant l'exécution :
 lablgl-runtime

dpkg -s ocaml gives :

Replaces: camlp4, ocaml-base
Provides: camlp4 (= 3.04-3), ocaml-base (= 3.04-3)
Depends: libc6 (>= 2.2.4-4), libncurses5 (>= 5.2.20010310-1), tcl8.3 (>=
8.3.0), tk8.3 (>= 8.3.0), xlibs (>> 4.1.0), libncurses5-dev
Recommends: ledit
Suggests: xlibs-dev, tcl8.3-dev, tk8.3-dev, ocaml-doc, emacsen
Conflicts: camlp4, ocaml-base

> > I solved this with using :
> > 
> > Depends: A | B
> 
>   Yes, I already experienced this.
> 
>   IIRC, this is documented in policy, i.e. when you want to depend on
>   a virtual package (or a provided package), you must have :

I will read up on this, but i think it is a bug in dpkg behavior.

>   Depends: <real package name providing B> | <virtual package name> 
> 
>   A = real package name providing B (there must be at least one)
>   B = virtual package name

and will this work when A is not installed, but another package providing B ?

Will look more into this.

Friendly,

Sven Luther