error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
  --> $DIR/repeat-expr-checks-wf.rs:6:13
   |
LL |     let a = [T::ASSOC; 2];
   |             ^^^^^^^^^^^^^ doesn't have a size known at compile-time
   |
   = help: the trait `Sized` is not implemented for `[u8]`
   = note: slice and array elements must have `Sized` type

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0277`.