error: missing fragment specifier --> $DIR/issue-39404.rs:3:19 | LL | macro_rules! m { ($i) => {} } | ^^ | = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #40107 = note: `#[deny(missing_fragment_specifier)]` on by default error: aborting due to previous error