$ rustc borrow2_bad.rs 
error[E0382]: use of moved value: `rect`
  --> borrow2_bad.rs:19:18
   |
18 |     compute_aera(rect); // 所有権が移動する
   |                  ---- value moved here
19 |     compute_side(rect); // ここでコンパイルエラーが出る
   |                  ^^^^ value used here after move
   |
   = note: move occurs because `rect` has type `Rectangle`, which does not implement the `Copy` trait

error: aborting due to previous error

For more information about this error, try `rustc --explain E0382`.