error[E0308]: mismatched types --> $DIR/issue-75801.rs:17:6 | LL | let _bar: u32 = $arg; | --- expected due to this ... LL | foo!("baz"); | ^^^^^ expected `u32`, found `&str` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0308`.