error: any use of this value will cause an error --> $DIR/const-len-underflow-separate-spans.rs:7:20 | LL | const LEN: usize = ONE - TWO; | -------------------^^^^^^^^^- | | | attempt to compute `1_usize - 2_usize`, which would overflow | = note: `#[deny(const_err)]` on by default = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #71800 error[E0080]: evaluation of constant value failed --> $DIR/const-len-underflow-separate-spans.rs:12:17 | LL | let a: [i8; LEN] = unimplemented!(); | ^^^ referenced constant has errors error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0080`. Future incompatibility report: Future breakage diagnostic: error: any use of this value will cause an error --> $DIR/const-len-underflow-separate-spans.rs:7:20 | LL | const LEN: usize = ONE - TWO; | -------------------^^^^^^^^^- | | | attempt to compute `1_usize - 2_usize`, which would overflow | = note: `#[deny(const_err)]` on by default = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #71800