error: this let-binding has unit value. Consider omitting `let _x =`
  --> $DIR/let_unit.rs:20:5
   |
LL |     let _x = println!("x");
   |     ^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `-D clippy::let-unit-value` implied by `-D warnings`

error: this let-binding has unit value. Consider omitting `let _a =`
  --> $DIR/let_unit.rs:24:9
   |
LL |         let _a = ();
   |         ^^^^^^^^^^^^

error: aborting due to 2 previous errors