error: struct `T1` is never constructed
  --> $DIR/unused-trait-with-assoc-ty.rs:3:8
   |
LL | struct T1;
   |        ^^
   |
note: the lint level is defined here
  --> $DIR/unused-trait-with-assoc-ty.rs:1:9
   |
LL | #![deny(dead_code)]
   |         ^^^^^^^^^

error: trait `Foo` is never used
  --> $DIR/unused-trait-with-assoc-ty.rs:5:7
   |
LL | trait Foo { type Unused; }
   |       ^^^

error: aborting due to 2 previous errors