Re: ports/181913: devel/qt4-script: /usr/include/c++/v1/type_traits:3175:22: error: call to 'swap' is ambiguous

On Sat, 7 Sep 2013 22:49:54 GMT
rakuco_at_FreeBSD.org wrote:

> Synopsis: devel/qt4-script: /usr/include/c++/v1/type_traits:3175:22:
> error: call to 'swap' is ambiguous
> 
> State-Changed-From-To: open->patched
> State-Changed-By: rakuco
> State-Changed-When: Sat Sep 7 22:47:43 UTC 2013
> State-Changed-Why: 
> I don't think the previous version worked.
> 
> From your description, it looks like you've switched to building with
> libc++ whereas libstdc++ was being used before.
> 
> The upcoming Qt 4.8.5 plus a few patches which only made it to 4.8.6
> (but we've backported) will finally make Qt build with libc++.
> 
> We've just sent an exp-run request for Qt 4.8.5, and will hopefully
> fix all these errors once it is committed.
> 
> http://www.freebsd.org/cgi/query-pr.cgi?pr=181913


I build the world/kernel since early this year with 

CXXFLAGS+=              -stdlib=libc++
CXXFLAGS+=              -std=c++11


in /etc/src.conf. I do not use those flags
in /etc/make.conf! /etc/src.conf is supposed to target ONLY
the /usr/src world, not the ports - this is as I interpret the man page
for /etc/src.conf and it would be logical. But this rule/thinking seems
to be broken by some includes from /usr/ports/Mk ingredients.

I can assure that I didn't switch anything to build the ports but
rebuilding world and then restarting building. Something must have
changed since then in the logic of how libc++ slipped in instead of
of libstdc++.

What I did was a "make delete-old-files", which deleted several GNU gcc
stuff on all CURRENT boxes. I did not see that any lib got killed after
I tried "make delete-old-libs". And I did not check whether libstdc++
is still being built.

There are many other occasions where now c++ errors occur and I guess
those ports need to be reported in one by one via PR?