1 error[E0428]: the name `b` is defined multiple times
2 --> $DIR/issue-58490.rs:18:5
4 LL | macro_rules! b { () => () }
5 | -------------- previous definition of the macro `b` here
7 LL | macro_rules! b { () => () }
8 | ^^^^^^^^^^^^^^ `b` redefined here
10 = note: `b` 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`.