Re: How to write emacs dependency ?

[Goswin von Brederlow <goswin-v-b@web.de>]

Paul Gevers <paul@climbing.nl> writes:

> Craig Small wrote:
>> On Wed, Nov 11, 2009 at 06:51:01PM +0100, Sven Joachim wrote:
>>> On 2009-11-11 16:43 +0100, Christoph Egger wrote:
>>>> Depends: emacs21 | emacs22 | emacs23 | xemacs21,
>>>>   gnus | emacs22 | emacs23 | xemacs21
>>> This does not give you any guarantee that somebody trying to run darcsum
>>> on emacs21 has the gnus package installed.
>> It does, let's say you have emacs21 installed but not gnus.
>> The first clause matches emacs21, so its satisfied.
>> The second, nothing matches, so you have an unmet dependency.
>> For instances off emacs22, emacs23 and xemacs21 then whatever is
>> installed meets both clauses.
>
> No it doesn't, if you have both emacs21 and emacs22 installed AND run
> darcsum on emacs21 (for whatever reason) you don't necessarily have
> gnus. So no guarantee with this string.
>
> Paul

dpkg can not express that. The dependency will always be fullfilled by
emacs22 being there.

Only way out is to go dirty and use plain

Depends: gnus | emacs22 | emacs23

gnus already depends on (x)emacs21.

MfG
        Goswin