Bug#746890: perl: ftbfs with GCC-4.9

[Dominic Hargreaves]

On Mon, May 05, 2014 at 08:19:04PM +0300, Niko Tyni wrote:
> On Sun, May 04, 2014 at 08:52:24AM +0100, Dominic Hargreaves wrote:
> > Control: forwarded -1 https://rt.perl.org/Ticket/Display.html?id=121505
> > Control: tags -1 +fixed-upstream
> > 
> > On Sun, May 04, 2014 at 12:22:21AM +0000, Matthias Klose wrote:
> > > The package fails to build in a test rebuild on at least amd64 with
> > > gcc-4.9/g++-4.9, but succeeds to build with gcc-4.8/g++-4.8. The
> > > severity of this report may be raised before the jessie release.
> 
> (Matthias already reported this earlier as #742818)
> 
> > This is fixed upstream for 5.20, which we're targetting for jessie
> > (releasing in the next month or so), so I think we don't need to do any
> > particular work in advance of that.
> 
> It's not fixed upstream yet AFAICS. But it is marked as blocking
> 5.20, so I expect it will be.

My understanding is that the following two commits, which are in blead,
fix the build failure:

commit 00051dd553979bd2a1dee100c324b59ee76a49e7
Author: H.Merijn Brand <h.m.brand at xs4all.nl>
Date:   Wed Apr 9 12:31:23 2014 +0200

    -fwrapv is broken prior to gcc-4.3 (googled and patched by Zefram)

commit 869747506fd0081f6c7eed149ec6f7adbcc4d5b1
Author: H.Merijn Brand <h.m.brand at xs4all.nl>
Date:   Wed Apr 9 11:16:55 2014 +0200

    gcc 4.9 by default does some optimizations that break perl (#121505)

    Patch by Tony Cook

There is some follow up in the upstream bug report: fixes for win32
compilation, and creating more tickets to represent the underlying issue.

Cheers,
Dominic.