Package segfaults when built with -O2 but not with -O0

[Andrew Haley]

On 11/18/2011 11:31 AM, Paul Howarth wrote:
> One of my packages, pptp, suffers occasional segfaults as reported in
> http://bugzilla.redhat.com/749455. However, whilst investigating this,
> it seems to be the case that simply rebuilding the package using no
> optimization (-O0) as opposed to the default -O2 is enough to stop this
> happening.
> 
> This raises two questions (at least!):
> 
> 1. Is it reasonable for me to flout the packaging guidelines by
> rebuilding with -O0 until this is resolved?
> 
> 2. How to determine what the actual problem is, e.g. a problem with the
> way the code is written leading to unsafe optimizations, or a gcc bug?

You're just going to have to debug it.

To start with, build with warnings, and look at them all.  If none of
that works and you're stuck, I'll have a look.

This is unlikely to be a gcc bug.

Does the upstream package segfault?

Andrew.