error[E0425]: cannot find value `msg` in this scope
  --> $DIR/trivial-diagnostics.rs:4:21
   |
LL |     struct_span_err(msg).emit();
   |                     ^^^ not found in this scope

error[E0425]: cannot find function `struct_span_err` in this scope
  --> $DIR/trivial-diagnostics.rs:4:5
   |
LL |     struct_span_err(msg).emit();
   |     ^^^^^^^^^^^^^^^ not found in this scope

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0425`.