error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
| ------------ ^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
= help: within `Cell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`, which is required by `{closure@$DIR/interior-mutability.rs:5:18: 5:20}: UnwindSafe`