Bug#1111004: transition: nanobind

[Drew Parsons <dparsons@debian.org>]

Package: release.debian.org
Followup-For: Bug #1111004

Emilio Pozuelo Monfort wrote:
> Unless I'm misunderstanding, the dependency should be in place (and in testing) 
> before the transition starts, so that when nanobind is uploaded with the new 
> ABI, britney will only migrate a set of packages that works, autopkgtest will be 
> scheduled with the right dependencies, and so on.

I meant that once the nanobind transition started in unstable, we
could upload the fenics patches to unstable.  That way the fenics
patches would only have to built once instead of twice (with binNMU),
and they would migrate to testing together with the new nanobind.

> So please upload fenics and any other rdep that needs to be patched, and let us 
> know when those are in testing.

I can start the uploads now. The process is slowed down by the gcc-15
transition. The new gcc-15 symbols change the nanobind ABI in a way
that is not reflected in old nanobind (python3-nanobind-abi15), so that
each fenics package has to be rebuilt one by one in order.
This fragility in the nanobind ABI is one of the issues addressed by
the new nanobind.

There is also a new openmpi version with some issues in unstable,
which will slow down transition of the rebuilt fenics packages to
testing.