+note: `Option<i32>` defined here
+ --> $SRC_DIR/core/src/option.rs:LL:COL
+ |
+LL | / pub enum Option<T> {
+LL | | /// No value.
+LL | | #[lang = "None"]
+LL | | #[stable(feature = "rust1", since = "1.0.0")]
+LL | | None,
+ | | ^^^^ not covered
+... |
+LL | | Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+LL | | }
+ | |_-