bug#32773: [PATCH] Fix clang libstdc++ header location search

[David Truby <David.Truby@arm.com>]

No problem, happy to help!

I'm also vaguely thinking if there's a way to upstream some of this
stuff in to clang so that we aren't patching it manually here. The same
file that we're patching has stuff specifically for other distros (e.g.
it has some Gentoo and Cray Linux specific fixes) so I don't think
they'd be opposed to accepting patches that are specific to Guix.
I'm not sure what the answer is there though, as we still need to patch
in the full path to the headers... maybe a cmake option and associated
macro to be used in that file? 

Not that this has any bearing on accepting these patches now, it's just
another thought for the future :)

David Truby

On Thu, 2019-11-14 at 17:54 +0100, Mathieu Othacehe wrote:
> > Applying both your patch and my patch works for me, in both pure
> > and
> > non-pure environments. I would suggest taht we also hide clang in
> > the
> > same way as gcc is hidden (in favour of clang-toolchain) to avoid
> > confusion, but otherwise it seems these two patches together at
> > least
> > get things to a working state!
> 
> Great! 
> 
> > I'd like to see make-clang-toolchain allow you to pick between a
> > specific libstdc++ or libc++, but that requires more thinking so I
> > think ideally it'd be better to apply these patches first to get
> > things
> > to a fixed state.
> 
> I agree. Let's wait to see if someone has objections and I'll push
> both
> patches in a few days.
> 
> Thanks for your support on this :)
> 
> Mathieu