error[E0381]: used binding `x` isn't initialized --> $DIR/uninit_local.rs:4:15 | LL | let x: bool; | - binding declared here but left uninitialized LL | while x {} | ^ `x` used here but it isn't initialized | help: consider assigning a value | LL | let x: bool = false; | +++++++ error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0381`.