error[E0391]: cycle detected when const-evaluating + checking `A`
  --> $DIR/issue-23302-3.rs:1:16
   |
LL | const A: i32 = B;
   |                ^
   |
note: ...which requires const-evaluating + checking `B`...
  --> $DIR/issue-23302-3.rs:3:16
   |
LL | const B: i32 = A;
   |                ^
   = note: ...which again requires const-evaluating + checking `A`, completing the cycle
note: cycle used when simplifying constant for the type system `A`
  --> $DIR/issue-23302-3.rs:1:1
   |
LL | const A: i32 = B;
   | ^^^^^^^^^^^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0391`.