pub trait WithAssoc {
  type Assoc;
  fn wa(&self) {}
}

pub trait Baz {}

pub trait Moo: WithAssoc
  where Self::Assoc: Baz // this is allowed
{}

pub trait Foo: Moo
// where Self::Assoc: Baz // but bound is not propagated
{
  fn foo(&self) {
    self.wa();
  }
}

fn main() {}