https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120147
--- Comment #5 from LIU Hao <lh_mouse at 126 dot com> --- issue seems to be that in `ac_fn_cxx_try_compile ()` there's } && test -s conftest.$ac_objext; then : which checks whether an object file is created, but the cmdline above has `-S` which produces an assembly file instead of an object file, causing the check to fail.