error[E0507]: cannot move out of `*x` which is behind a raw pointer
  --> $DIR/borrowck-move-from-unsafe-ptr.rs:2:13
   |
LL |     let y = *x;
   |             ^^ move occurs because `*x` has type `Box<isize>`, which does not implement the `Copy` trait
   |
help: consider removing the dereference here
   |
LL -     let y = *x;
LL +     let y = x;
   |
help: consider cloning the value if the performance cost is acceptable
   |
LL -     let y = *x;
LL +     let y = x.clone();
   |

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0507`.