Re: [GSoC] blends-gen-control hints (Was: blends-dev, gsoc 2013)

[Emmanouil Kiagias <e.kiagias@gmail.com>]

Hello Andreas,

On Fri, Jul 26, 2013 at 6:18 PM, Andreas Tille <andreas@an3as.eu> wrote:

Yes.  That's the reason why you can not simply take the first
alternative.  I'm not sure what might be the proper solution here.  It
comes to mind to inject all real packages of an alternatives sequence
(just droping the virtual packages) which is another "interpretation"
of the technical term "alternative" - but tasksel just does not know
such things like alternatives and IMHO it is better to have a bit more
than loosing something.

As you said I now include all the real packages of an alternative sequence in the tasksel template. Then when it comes to generate a tasksel.<arch> I use a regex where I keep the first available package of each alternative sequence and I remove the rest. It may be a little dirty but seems to work. Now tasksel template generates identical files which the tasksel.<arch> files. Only difference is in debian-science where there is a difference in the single packages sequence(sorting difference, does this cause any problem?).

However, there could be some problem to install one task in case there
might be *conflicting* packages.  So in case we inject "full set of
alternatives" into taskdesc files we either need to query packages table
for conflicts or we might enrich our blends tables in advance with
potentially conflicting packages.  I guess this might be a very rare
case but as always its the single case amongst millions which couses
trouble for the programmer ...

Petter, what do you think?

This problem then may also occur in the previous {sec-}blend-gen-control(I did not quite understand the case)? That means that  we should check for conflicting packages between all task-description packages(per task)? Or it is just between the alternatives?  The way I solved the previous problem it is the same way we handle the alternatives in tasksel in all cases(I keep the first available and I remove the rest). 

Yes.  Usually Petter is very reliable.  If he does not answer he is most
probable on VAC.

;-)

Kind regards 

Emmanouil