Bug#838613: perl: FTBFS on hppa - ext/XS-APItest/t/customop FAILED

[Niko Tyni]

On Fri, Sep 23, 2016 at 07:44:13AM -0400, John David Anglin wrote:
> On 2016-09-23, at 2:24 AM, Niko Tyni wrote:
> > On Thu, Sep 22, 2016 at 08:49:42PM -0400, John David Anglin wrote:

> >> Since 5.22.2-4, the ext/XS-APItest/t/customop test fails on hppa and perl
> >> fails to build from source.  For example, see:
> >> https://buildd.debian.org/status/fetch.php?pkg=perl&arch=hppa&ver=5.22.2-5&stamp=1474392510
> > 
> > There are earlier cases of this on experimental buildds. The oldest I
> > see is 5.22.1-6. It looks like this regressed with gcc 6.

I got hppa shell access from Helge, some results:

- building with gcc-5 or at -O0 makes it go away
- I've bisected with gcc #pragmas that disabling optimization for just
  Perl_custom_op_register() in op.c makes it go away
- I haven't managed to find which specific optimization causes it

If nothing else, we can set the optimization level for op.c to -O0 in
cflags.SH on hppa. Of course even better if somebody can find a more
targeted deoptimization and/or the underlying reason (whether a code
bug or a gcc optimizer one.) I don't intend to work much on that myself.

As the Perl 5.24 transition is currently ongoing in unstable, I don't
think we want to do a perl upload for the sake of a non-release arch
before the transition is over.  At the same time, I expect missing the
500+ transition binNMUs from the release team is inconvenient for the
hppa porters.

Maybe you could manually upload a DEB_BUILD_OPTIONS=noopt build of 5.24
for now, unless you have a separate hppa-specific package repository
where a sourceful fix could go?
-- 
Niko Tyni   ntyni at debian.org