Bug#770290: libblas3: please convert to multiarch

[Sébastien Villemot]

Dear Dima,

Le lundi 20 mars 2017 à 00:12 -0700, Dima Kogan a écrit :

> The main proposal from #760936 was to manage a separate alternative
> for each architecture. There's precedent for this at least in
> src:petsc and src:s2tc.
> 
> I'm attaching a patch series that applies this idea here. The patches
> mostly work. There're at least two bugs here that need to be dealt
> with, and I can work on those. But in the meantime, let's decide that
> this is the approach we want to pursue.

Thanks for raising up this issue, and for providing preliminary
patches.

I agree with the general approach, and I have committed your patches on
a new git branch named "multiarch".

I have also added two commits, for fixing a bug in your patches, and
for removing the libblas-common package which will be obsoleted by this
move.

> The issues:

> 1. Something is wrong with libblas.a. It ends up mostly empty for me

This was a separate issue, which is now fixed (see #863258).

> 2. There's now a separate set of alternatives for each arch called
> something like blas-ARCH. Installing one of the new packages creates
> these new alternatives, but doesn't remove the old alternatives,
> which end up as a broken link.

Indeed. If you have time, don't hesitate to provide a patch (or even
better, to commit it directly to the git branch).

> Clearly, we'd also need to update the other packages that provide
> BLAS implementations, but let's do this one step at a time.

Indeed, once we have agreed on an implementation for lapack, we need to
apply similar changes to openblas and atlas, and also add versioned
breaks between the various packages (to avoid coexistence of the old
and the new alternatives system).

Then we will do a simultaneous upload of the 3 packages, first to
experimental.

Cheers,

-- 
 .''`.    Sébastien Villemot
: :' :    Debian Developer
`. `'     http://sebastien.villemot.name
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