[pkg-boost-devel] Bug#506939: Bug#506939: boost: setting CFLAGS in debian/rules clobbers environment

[Steve Langasek]

On Wed, Nov 26, 2008 at 02:01:53AM -0600, Steve M. Robbins wrote:
> Hi Steve,

> Bjam is built twice: first using "build.sh" then the newly-built bjam
> is used to build the "real" bjam that is used for subsequently
> building Boost.

Right, I overlooked that fact; that's a reason why build flags set in the
environment are likely to be less important, although there's still a slight
win on elegance by not having to repeat the flag name in two places.

> On Tue, Nov 25, 2008 at 11:18:19PM -0800, Steve Langasek wrote:

> > I see in the latest version of boost that you're setting
> > CFLAGS=-fno-strict-aliasing directly in debian/rules.  This is somewhat
> > suboptimal; first, because there's already a patch in the package
> > (debian/patches/bjam-no-strict-aliasing) to do exactly this,

> The patch bjam-no-strict-aliasing only applies to the second build
> (using the bootstrap bjam).  We need to supply
> CFLAGS=-fno-strict-aliasing on the first bjam build because otherwise
> the first bjam segfaults on some architectures, e.g. alpha [1].

That's true if not specifying the gcc profile when building; if you do (as
in the Ubuntu patch), then it applies equally well to both builds.  I know
this to be true because the Ubuntu patch was added to address the exact same
issue, but I've also tested that the Ubuntu package builds exactly as
intended on alpha, too.

> In short: I think the Debian package is correct as-is and I don't believe
> changes are needed.  Do you agree?

C.f. "elegance" above - I think it's a very minor change, but that it would
still be an improvement.

Cheers,
-- 
Steve Langasek                   Give me a lever long enough and a Free OS
Debian Developer                   to set it on, and I can move the world.
Ubuntu Developer                                    http://www.debian.org/
slangasek at ubuntu.com                                     vorlon at debian.org