https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103341
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Reduced with an extra testcase from PR 103706: template<class T, class U> concept C = sizeof(T) == sizeof(int); template<class T> inline constexpr C<T> auto trait_v{1}; decltype(trait_v<int>) t = 1; template<typename T> void g5() { []() -> C<T> auto{ return T(); }(); } template void g5<int>();