https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80516
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The error message with -pedantic is now:
<source>:7:3: error: 'signed' specified with typedef-name 'using u = unsigned
int' [-Wpedantic]
7 | S<signed u> s;
| ^~~~~~
