error[E0277]: the size for values of type `Self` cannot be known at compilation time
  --> $DIR/issue-63593.rs:9:17
   |
LL |     type This = Self;
   |                 ^^^^ doesn't have a size known at compile-time
   |
note: required by a bound in `MyTrait::This`
  --> $DIR/issue-63593.rs:9:5
   |
LL |     type This = Self;
   |     ^^^^^^^^^^^^^^^^^ required by this bound in `MyTrait::This`
help: consider further restricting `Self`
   |
LL | trait MyTrait: Sized {
   |              +++++++

error: aborting due to previous error

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