https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71063
--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> --- FWIW, my fix was --- a/gcc/opts.c +++ b/gcc/opts.c @@ -1641,6 +1641,11 @@ common_handle_option (struct gcc_options *opts, { ++ a; pflags = & exclude_flags; + if (*a == '\0') + { + error_at (loc, "missing argument to %qs", "--help=^"); + break; + } } else pflags = & include_flags;