https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97308
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- The /lib/cpp error is a bit misleading, because that's the last thing it tries to find as a C++ compiler, after exhausting g++ -std=c++11 and various other options that fail with: configure:19863: g++ -std=c++11 -E conftest.cpp cc1plus: error: unrecognized command line option "-std=c++11" As stated in the install docs, you need a C++11 compiler, and the system GCC on OpenBSD probably doesn't recognise the -std=c++11 option. This is not a bug.
