Bug#1141561: transition: c-blosc2

On 13/07/2026 06:42, Antonio Valentino wrote:
> Dear Emilio,
> 
> On Mon, 6 Jul 2026 19:54:28 +0200 Emilio Pozuelo Monfort
> <[email protected]> wrote:
>> Control: tags -1 moreinfo
>>
>> On 06/07/2026 10:49, Antonio Valentino wrote:
>>> Package: release.debian.org
>>> Severity: normal
>>> X-Debbugs-Cc: [email protected], [email protected]
>>> Control: affects -1 + src:c-blosc2
>>> User: [email protected]
>>> Usertags: transition
>>>
>>> Dear release team,
>>>
>>> the upgrade from c-blosc2 v2.23.1 to v3.1.5 requires a change in the
>>> SONAME and hence a transition. The new version is already in experimental.
>>> The following source packages need to be rebuilt:
>>>
>>> * adios2
>>> * groonga
>>> * pytables
>>> * zmat
>>>
>>> I have tested the above packages with the new version of c-blosc2.
>>> Only for pytables it was necessary a small patch that has been already
>>> uploaded.
>>>
>>> pytables 3.11.1-2 is now in unstable and it should migrate to testing in
>>> 5 days.
>>>
>>> Apart for that all the packages build successfully with the new c-blosc2
>>> version that is currently in experimental.
>>
>> There's a few build failures in experimental:
>>
>> https://buildd.debian.org/status/package.php?p=c-blosc2&suite=experimental
>>
>> Please fix those in experimental first.
> 
> Thanks for the quick reply.
> According to [1] 32bit architectures are no longer supported in c-blosc2
> v3.x.
> 
> My plan would be just to request the removal of c-blosc2 package for
> i386 and armhf from sid.
> According to my understanding this should unblock the migration of the
> new new c-blosc2 package to testing in a normal situation.
> I'm not sure if this is fine for a transition (like in this case).
> Do you have comments or any advice?

You also need to request removal of reverse-(build-)dependencies, recursively. 
According to my dak foo, there's a lot of rdeps, since pytables build-depends on 
libblosc2-dev. There's other stuff, such as pandas, vtk9... You can run `dak rm 
-Rn c-blosc2` on coccia, or play with `build-rdeps` and `apt-cache rdepends`.

If this has to happen, then it should happen in sid *before* the transition 
starts, since the package removals can happen with the current version in sid. 
Basically you'll have to find the set of packages that need to be dropped, then 
file bugs against ftp.debian.org for each source package.

Cheers,
Emilio