1 error[E0428]: the name `foo` is defined multiple times
2 --> $DIR/issue-38715.rs:5:1
4 LL | macro_rules! foo { ($i:ident) => {} }
5 | ---------------- previous definition of the macro `foo` here
7 LL | macro_rules! foo { () => {} }
8 | ^^^^^^^^^^^^^^^^ `foo` redefined here
10 = note: `foo` must be defined only once in the macro namespace of this module
12 error: aborting due to previous error
14 For more information about this error, try `rustc --explain E0428`.