Bug#754125: libimager-perl: FTBFS on s390x

[Aurelien Jarno]

On Mon, Jul 14, 2014 at 11:44:22PM +0300, Niko Tyni wrote:
> (Cc'ing the libpng maintainers.)
> 
> On Sun, Jul 13, 2014 at 08:12:38PM +0200, Aurelien Jarno wrote:
> 
> > A quick debugging seems to show the problem is on the libpng side.
> > Rebuilding it makes the problem disappear. It looks like it is due to
> > the same issue we are doing this transition, ie the libpng structure
> > expose a jmp_buf structure. I don't really now what to do...
> 
> Ouch. I see. From png.h:
> 
> struct png_struct_def
> {
> #ifdef PNG_SETJMP_SUPPORTED
>    jmp_buf jmpbuf;            /* used in png_error */
> #endif
> [...]
> 
> PNG_SETJMP_SUPPORTED seems to be the default, if I read pngconf.h
> correctly.
> 
> As libpng was built against libc6-dev_2.17-97 168 days ago and hasn't
> been binNMU'd since, does that mean that all its reverse dependencies
> built against libc6 2.19 (in the last month or so) are potentially broken
> on s390x?  Or do I misunderstand something?

You are correct :-( Currently it seems to not break too much, but as
soon as libpng will be rebuilt, it will break a lot of things...

> Doesn't the fact that it's at the start of the struct make things
> even worse?

Indeed, it *might* have worked if it was at the end.

> There are 500ish packages depending on libpng12-0. So do we need
> an SONAME bump on s390x only? How hard would that be?

I think it is urgent to wait to decide about a global strategy how to
handle that. Upstream suggested to do like Red Hat, ie just rebuild
everything and warn the users their system might break during upgrade.

I have sent a mail to debian-s390 so that we can decide on a strategy.

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien at aurel32.net                 http://www.aurel32.net