error[E0391]: cycle detected when computing the bounds for type parameter `T` --> $DIR/issue-21177.rs:6:21 | LL | fn foo>() { } | ^^^^ | = note: ...which immediately requires computing the bounds for type parameter `T` again note: cycle used when computing explicit predicates of `foo` --> $DIR/issue-21177.rs:6:21 | LL | fn foo>() { } | ^^^^ = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0391`.