error[E0080]: evaluation of constant value failed --> $DIR/const-len-underflow-separate-spans.rs:10:20 | LL | const LEN: usize = ONE - TWO; | ^^^^^^^^^ attempt to compute `1_usize - 2_usize`, which would overflow note: erroneous constant encountered --> $DIR/const-len-underflow-separate-spans.rs:14:17 | LL | let a: [i8; LEN] = unimplemented!(); | ^^^ error: aborting due to previous error For more information about this error, try `rustc --explain E0080`.