error[E0277]: the trait bound `Box<T>: Copy` is not satisfied
  --> $DIR/issue-74824.rs:8:5
   |
LL |     type Copy<T>: Copy = Box<T>;
   |     ^^^^^^^^^^^^^^----^^^^^^^^^^
   |     |             |
   |     |             required by this bound in `UnsafeCopy::Copy`
   |     the trait `Copy` is not implemented for `Box<T>`

error[E0277]: the trait bound `T: Clone` is not satisfied
  --> $DIR/issue-74824.rs:8:5
   |
LL |     type Copy<T>: Copy = Box<T>;
   |     ^^^^^^^^^^^^^^----^^^^^^^^^^
   |     |             |
   |     |             required by this bound in `UnsafeCopy::Copy`
   |     the trait `Clone` is not implemented for `T`
   |
   = note: required because of the requirements on the impl of `Clone` for `Box<T>`
help: consider restricting type parameter `T`
   |
LL |     type Copy<T: Clone>: Copy = Box<T>;
   |                ^^^^^^^

error: aborting due to 2 previous errors

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