error[E0391]: cycle detected when computing the super predicates of `T1` --> $DIR/issue-12511.rs:1:12 | LL | trait T1 : T2 { | ^^ | note: ...which requires computing the super predicates of `T2`... --> $DIR/issue-12511.rs:5:12 | LL | trait T2 : T1 { | ^^ = note: ...which again requires computing the super predicates of `T1`, completing the cycle note: cycle used when collecting item types in top-level module --> $DIR/issue-12511.rs:1:1 | LL | / trait T1 : T2 { LL | | LL | | } | |_^ error: aborting due to previous error For more information about this error, try `rustc --explain E0391`.