https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81372
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- --disable-hosted-libstdcxx means are not producing a hosted libstdc++ but compiling GCC requires a hosted C++ Library (for stage 2). Really any native GCC will require a hosted C++ Library. There is no reason to use --disable-hosted-libstdcxx except for a cross compiler where there is another standard C++ library that will be used.
