Title: GCC 5 Defaults to the New C++11 ABI Author: Mike Frysinger Content-Type: text/plain Posted: 2015-10-22 Revision: 2 News-Item-Format: 1.0 Display-If-Installed: >=sys-devel/gcc-5 GCC 5 uses the new C++ ABI by default. When building new code, you might run into link time errors that include lines similar to: ...: undefined reference to '_ZNSt6chrono12steady_clock3nowEv@GLIBCXX_3.4.17' Or you might see linkage failures with "std::__cxx11::string" in the output. These are signs that you need to rebuild packages using the new C++ ABI. You can quickly do so by using revdep-rebuild (from gentoolkit). For gentoolkit-0.3.1 or higher: # revdep-rebuild --library 'libstdc++.so.6' -- --exclude gcc For previous versions of gentoolkit: # revdep-rebuild --library 'libstdc\+\+\.so\.6' -- --exclude gcc For more details, feel free to peruse: https://developerblog.redhat.com/2015/02/05/gcc5-and-the-c11-abi/ https://blogs.gentoo.org/blueness/2015/03/10/the-c11-abi-incompatibility-problem-in-gentoo/