https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61758
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- It is totally unsupported (and unlikely to work) to mix C++11 code built with GCC 4.x and 4.y, for any x!=y Mixing code built with 4.8.x and 4.8.y should work, and does with the default configuration. You didn't actually provide the information required by http://gcc.gnu.org/bugs such as the output of 'gcc -v' but I assume you're building GCC with --enable-libstdcxx-time, in which case there are fewer guarantees. If Gentoo is using that option (which should not be necessary with GCC 4.8 anyway) then you need to rebuild all the libraries that depend on the <chrono> types. We could potentially export a steady_clock::now() compatibility symbol for the --enable-libstdcxx-time config, but I'd prefer to see that option go away rather than keep it on life support.
