error: reference to the macro call's crate, which is rarely intended
  --> $DIR/crate_in_macro_def.rs:19:28
   |
LL |             println!("{}", crate::unhygienic::MESSAGE);
   |                            ^^^^^
   |
   = note: `-D clippy::crate-in-macro-def` implied by `-D warnings`
help: if reference to the macro definition's crate is intended, use
   |
LL |             println!("{}", $crate::unhygienic::MESSAGE);
   |                            ~~~~~~

error: aborting due to previous error