error[E0391]: cycle detected when computing the super predicates of `A`
  --> $DIR/cyclic-trait-resolution.rs:1:1
   |
LL | trait A: B + A {}
   | ^^^^^^^^^^^^^^
   |
note: ...which requires computing the super traits of `A`...
  --> $DIR/cyclic-trait-resolution.rs:1:14
   |
LL | trait A: B + A {}
   |              ^
   = note: ...which again requires computing the super predicates of `A`, completing the cycle
note: cycle used when collecting item types in top-level module
  --> $DIR/cyclic-trait-resolution.rs:1:1
   |
LL | trait A: B + A {}
   | ^^^^^^^^^^^^^^^^^

error: aborting due to previous error

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