https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81004
--- Comment #12 from Azat <a3at.mail at gmail dot com> --- > Started with r238959. If you revert this then it fixes some of problems (even though this is a temporary solution), but there are more, and now this is *only without -flto* (i.e. -Wall "-Werror -Wunknown-pragmas -Wextra -Wwrite-strings -std=c++1z -g3 '-rdynamic"): /usr/include/c++/7.1.1/bits/regex.h:235: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::data()' /usr/include/c++/7.1.1/bits/regex.h:235: undefined reference to `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::data()' I will try to get a small reproducer later.
