error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters --> $DIR/issue-86756.rs:1:14 | LL | trait Foo {} | - ^ already used | | | first use of `T` error[E0412]: cannot find type `dyn` in this scope --> $DIR/issue-86756.rs:5:10 | LL | eq:: | ^^^ not found in this scope warning: trait objects without an explicit `dyn` are deprecated --> $DIR/issue-86756.rs:5:15 | LL | eq:: | ^^^ | = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021! = note: for more information, see = note: `#[warn(bare_trait_objects)]` on by default help: if this is an object-safe trait, use `dyn` | LL | eq:: | +++ error[E0107]: missing generics for trait `Foo` --> $DIR/issue-86756.rs:5:15 | LL | eq:: | ^^^ expected at least 1 generic argument | note: trait defined here, with at least 1 generic parameter: `T` --> $DIR/issue-86756.rs:1:7 | LL | trait Foo {} | ^^^ - help: add missing generic argument | LL | eq::> | +++ error: aborting due to 3 previous errors; 1 warning emitted Some errors have detailed explanations: E0107, E0403, E0412. For more information about an error, try `rustc --explain E0107`.