Weird interaction between higher-ranked lifetimes and associated type bounds

[apasel422]

foo.rs:

pub trait Foo
where
    for<'a> &'a Self: Bar,
    for<'a> <&'a Self as Bar>::Xyz: Clone {}

pub trait Bar {
    type Xyz;
}

impl Foo for () {}

impl<'a> Bar for &'a () {
    type Xyz = usize;
}

Error from rustc 1.0.0-nightly (30e1f9a1c 2015-03-14) (built 2015-03-15)

foo.rs:12:1: 12:19 error: the trait `for<'a> core::clone::Clone` is not implemented for the type `<&'a () as Bar>::Xyz` [E0277]
foo.rs:12 impl Foo for () {}
          ^~~~~~~~~~~~~~~~~~

[brson]

Current error

rustc 1.17.0 (56124baa9 2017-04-24)
error[E0277]: the trait bound `for<'a> <&'a () as Bar>::Xyz: std::clone::Clone` is not satisfied
  --> <anon>:10:6
   |
10 | impl Foo for () {}
   |      ^^^ the trait `for<'a> std::clone::Clone` is not implemented for `<&'a () as Bar>::Xyz`
   |
   = help: the following implementations were found:
             <&'a T as std::clone::Clone>
   = note: required by `Foo`

error: aborting due to previous error

Compilation failed.

[steveklabnik]

Triage: no change

[estebank]

Trieage: no change.

[estebank]

This code now compiles since 1.56. On 1.55, the error was:

error[E0277]: the trait bound `for<'a> <&'a () as Bar>::Xyz: Clone` is not satisfied
  --> <source>:10:6
   |
1  | pub trait Foo
   |           --- required by a bound in this
...
4  |     for<'a> <&'a Self as Bar>::Xyz: Clone {}
   |                                     ----- required by this bound in `Foo`
...
10 | impl Foo for () {}
   |      ^^^ the trait `for<'a> Clone` is not implemented for `<&'a () as Bar>::Xyz`
   |
   = help: the following implementations were found:
             <&T as Clone>