https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116777
--- Comment #7 from Iain Sandoe <iains at gcc dot gnu.org> --- as noted in several places; the long-term solution for Darwin (in general since there's an installed /usr/lib/libstdc++.6.dylib even on modern systems) - is for use to use an inline namespace for libstdc++ (always). When that is done, there's no conflict with the older installed .6.dylib s. This work is not finished yet, I have some hacks but not coherent enough to want to put them in the wild. This and Apple blocks are the two biggest issues in making GCC better on Darwin.
