tests/ui/macros/issue-35450.rs - rust - Git at Google

 macro_rules! m { ($($t:tt)*) => { $($t)* } }

 fn main() {
     m!($t); //~ ERROR cannot find macro parameter `$t` in this scope
 }
	macro_rules! m { ($($t:tt)) => { $($t) } }

	fn main() {
	m!($t); //~ ERROR cannot find macro parameter `$t` in this scope
	}