1 error[E0767]: use of unreachable label `'a`
2 --> $DIR/issue-73541-2.rs:7:26
5 | -- unreachable label defined here
8 | ^^ unreachable label `'a`
11 | ---- in this macro invocation
13 = note: labels are unreachable through functions, closures, async blocks and modules
14 = note: this error originates in the macro `b` (in Nightly builds, run with -Z macro-backtrace for more info)
16 error: aborting due to previous error
18 For more information about this error, try `rustc --explain E0767`.