Debug not defined for custom BuildHasher

[anthok]

Can repro with something like below.

let s = BuildHasherDefault::<FxHasher>::default();
let mut cache: LruCache<isize, &str, BuildHasherDefault<FxHasher>> = LruCache::unbounded_with_hasher(s);
std::println!("{:?}", cache);



`LruCache<isize, &str, BuildHasherDefault<FxHasher>>` doesn't implement `Debug`