We caught a report due to _GLIBCXX_USE_CXX11_ABI and abi:cxx11. We are upstream, and it appears Debian built the library using GCC and _GLIBCXX_USE_CXX11_ABI was in effect. A user then came along with Clanf and compiled the userland program. The link failed. This is expected given our understanding of the landscape. We found "GCC5 and the C++11 ABI", https://developerblog.redhat.com/2015/02/05/gcc5-and-the-c11-abi/. The pages says: Providers of such libraries or interfaces need to consider whether they want to provide ABI coexistence, like libstdc++ does, or require their users to rebuild. I read the Red Hat blog post, but its not clear to me how to accomplish the coexistence. That is, I want to ensure the library that Debian builds has a symbol in both namespace so linking can occur with either GCC or Clang and "things just work" for the user. How is libstdc++ providing symbols in both namespaces? How do I ensure the symbol is present in both namesspaces so "things just work" for a user? Thanks in advance.
