Bug#1109176: Broken liblapacke:amd64 Breaks on libatlas3-base

[M. Zhou]

I disagree. You may have incorrectly understood the package
relationship here.

The binary package liblapacke is not a transitional package.
The latest liblapacke cannot provide what the old libatlas3-base
package provides. Instead, libatlas3-base is always a candidate
that may serve as a dependency of liblapacke. After some
point, libatlas3-base get removed, and hence existing packages
depending on libatlas3-base has to be built against the other
blas/lapack impelementations.

The original Breaks relationship is due to the underlying
update-alternatives mechanism. We are sure liblapacke does
not work with libatlas3-base as the actual implementation.

The correct solution is to simply ask apt to get rid of
libatlas3-base. Please do not introduce a NEW binary package.
This is not transition. This is deprecation, which is
exactly Breaks+Repalces does.

Let me handle this bug. I'm co-maintainer of src:lapack.

On Sat, 2025-07-19 at 17:06 +0200, Jochen Sprickerhof wrote:
> Hi,
> 
> I looked into it a bit more and got it working with a transitional dummy 
> package as described here:
> 
> https://wiki.debian.org/RenamingPackages
> 
> I have added this to lapack:
> 
> Package: libatlas3-base
>   Depends: libblas3, ${misc:Depends}
>   Architecture: all
>   Priority: optional
>   Section: oldlibs
>   Description: transitional package
>    This is a transitional package. It can safely be removed.
> 
> As it is already late for trixie I uploaded it to NEW/experimental. The 
> release team agreed to take it afterwards. I will take care of the rest 
> unless someone disagrees with the approach.
> 
> Cheers Jochen
> 
> 
> * Jochen Sprickerhof <jspricke at debian.org> [2025-07-18 10:26]:
> > Hi,
> > 
> > * M. Zhou <lumin at debian.org> [2025-07-17 22:35]:
> > > I'm still a little bit confused about the report.
> > > 
> > > Based on the podman image debian:bookwork, I can upgrade psfex without apt
> > > reporting issue like reported. So the problem seems to be highly specific
> > > to the -14 revision of atlas.
> > 
> > There is a reproducer in the initial bug report that is still valid 
> > for me.
> > 
> > > Do that mean making lapack break the -14 version is enough to fix this bug?
> > > ```
> > > -        libatlas3-base (<< 3.10.3-14)
> > > +        libatlas3-base
> > > ```
> > 
> > From a quick look libatlas3-base in bookworm was split into multiple 
> > packages and there is a Break: but no Replaces: see
> > 
> > https://wiki.debian.org/PackageTransition
> > 
> > I think #7 applies.
> > 
> > Cheers Jochen
>