error[E0326]: implemented const `BAR` has an incompatible type for trait
  --> $DIR/associated-const-impl-wrong-type.rs:8:16
   |
LL |     const BAR: u32;
   |                --- type in trait
...
LL |     const BAR: i32 = -1;
   |                ^^^ expected `u32`, found `i32`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0326`.
