error: generic parameters may not be used in const operations
  --> $DIR/issue-67945-3.rs:11:23
   |
LL |         let x: Option<S> = None;
   |                       ^ cannot perform const operation using `S`
   |
   = note: type parameters may not be used in const expressions
   = help: use `#![feature(generic_const_exprs)]` to allow generic const expressions

error[E0392]: parameter `S` is never used
  --> $DIR/issue-67945-3.rs:9:12
   |
LL | struct Bug<S> {
   |            ^ unused parameter
   |
   = help: consider removing `S`, referring to it in a field, or using a marker such as `PhantomData`
   = help: if you intended `S` to be a const parameter, use `const S: usize` instead

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0392`.