error[E0308]: mismatched types --> $DIR/issue-3680.rs:3:9 | LL | match None { | ---- this expression has type `Option<_>` LL | Err(_) => () | ^^^^^^ expected `Option<_>`, found `Result<_, _>` | = note: expected enum `Option<_>` found enum `Result<_, _>` help: try wrapping the pattern in `Some` | LL | Some(Err(_)) => () | +++++ + error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0308`.