Bug#1121084: perl built with new IEEE long doubles on ppc64el breaks pdl

[Niko Tyni]

Control: clone -1 -2
Control: reassign -1 pdl 1:2.100-2
Control: retitle -1 pdl: please build-depend on gcc (>= 4:15) [ppc64el] for IEEE long double transition
Control: tag -1 trixie sid
Control: block -2 with -1

On Thu, Nov 20, 2025 at 08:03:54PM +0100, Sebastiaan Couwenberg wrote:
> On 11/20/25 7:42 PM, Niko Tyni wrote:
> > This smells like an ABI change in the interface between perl and binary
> > ("XS") modules. I wonder if we can (or should) get away with just
> > handling pdl, or if we need to bump the Provides: perlapi-5.40.1
> > and force rebuilds of all binary modules.
> 
> It's unlikely that there are actual users of pdl on ppc64el, so I don't think this warrants great effort.
> 
> If rebuilding pdl resolves the issue, let's leave it at that.
> 
> Unless you really want to spend the time for the sake of correctness.
> 
> I acknowledge that pdl could just be the canary and wereas it is not important on ppc64el, perl itself is.

Thanks Bas, and sorry for the delay.

I propose that we add an explicit Build-Depends: gcc (>= 4:15) [ppc64el]
to src:pdl (say) 1:2.100-2, and then a Breaks: pdl (<< 1:2.100-2) [ppc64el]
to perl-base. That should ensure that partial upgrades stay working AFAICS,
and I hope the testing migration checks will automatically pick up the
hint about migrating them together.

Hope that makes sense. It doesn't seem like great effort to me, and is
IMO cleaner than just papering over this with a no-change rebuild. If
you think it's badly overkill, feel free to just rebuild src:pdl and
then close the pdl bug.
-- 
Niko