error[E0004]: non-exhaustive patterns: `UnstableEnum::Unstable` not covered --> $DIR/unstable-gated-patterns.rs:10:11 | LL | match UnstableEnum::Stable { | ^^^^^^^^^^^^^^^^^^^^ pattern `UnstableEnum::Unstable` not covered | note: `UnstableEnum` defined here --> $DIR/auxiliary/unstable.rs:11:5 | LL | pub enum UnstableEnum { | --------------------- ... LL | Unstable, | ^^^^^^^^ not covered = note: the matched value is of type `UnstableEnum` help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown | LL ~ UnstableEnum::Stable2 => {} LL + UnstableEnum::Unstable => todo!() | error: aborting due to previous error For more information about this error, try `rustc --explain E0004`.