dbusmenu-qt5 build failure on 10.7 and 10.8 buildbots because of using libstdc++

[Lawrence Velázquez]

> On Oct 7, 2016, at 11:11 AM, René J.V. Bertin <rjvbertin at gmail.com> wrote:
> 
> On Friday October 07 2016 10:51:59 Lawrence Velázquez wrote:
> 
>> Not to mention the fact that literally every single C++ port would have
>> to declare a library dependency on libgcc.
> 
> Or not: if a compiler selection mechanism is used that picks
> a macports-gcc version that dependency would be added indirectly, no?
> I'd find it more intuitive to invoke such a mechanism than declare
> a dependency on something we're used to take for granted...

Currently, if you set "configure.compiler macports-gcc-XYZ",
a dependency on gccXYZ is added automatically. A direct dependency on
libgcc is not added because we don't know what the port wants to use gcc
for. It currently works out because gcc* already depends on libgcc, but
the dependency tree is not actually correct.

The current mechanism for adding these dependencies is coarse. It
considers each of Clang / GCC / DragonEgg (RIP) to be a sort of compiler
collection and assumes that ports aren't going to mix and match. There
are many ports that do in fact mix and match (notably for Fortran), so
it might be useful to refine this mechanism to allow something like
"configure.compiler.cxx macports-gcc-XYZ", which would add a direct
library dependency on libgcc (among other things).

vq