error[E0391]: unsupported cyclic reference between types/traits detected
  --> $DIR/issue-23302-2.rs:14:9
   |
14 |     A = Y::B as isize, //~ ERROR E0391
   |         ^^^^^^^^^^^^^ cyclic reference
   |
note: the cycle begins when const-evaluating `Y::A::{{initializer}}`...
  --> $DIR/issue-23302-2.rs:14:5
   |
14 |     A = Y::B as isize, //~ ERROR E0391
   |     ^^^^^^^^^^^^^^^^^
   = note: ...which then again requires const-evaluating `Y::A::{{initializer}}`, completing the cycle.

error: aborting due to previous error