error: unused variable: `unused`
  --> $DIR/lint-removed-allow.rs:8:17
   |
LL | fn main() { let unused = (); }
   |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
   |
note: the lint level is defined here
  --> $DIR/lint-removed-allow.rs:7:8
   |
LL | #[deny(unused_variables)]
   |        ^^^^^^^^^^^^^^^^

error: aborting due to previous error