Trait objects need to have all associated types specified. Erroneous code
example:
```compile_fail,E0191
trait Trait {
type Bar;
}
type Foo = Trait; // error: the value of the associated type `Bar` (from
// the trait `Trait`) must be specified
```
Please verify you specified all associated types of the trait and that you
used the right trait. Example:
```
trait Trait {
type Bar;
}
type Foo = Trait<Bar=i32>; // ok!
```