error[E0277]: the type `UnsafeCell` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary --> $DIR/not-panic-safe-5.rs:9:14 | LL | assert::<*const UnsafeCell>(); | ^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary | = help: the trait `RefUnwindSafe` is not implemented for `UnsafeCell`, which is required by `*const UnsafeCell: UnwindSafe` = note: required for `*const UnsafeCell` to implement `UnwindSafe` note: required by a bound in `assert` --> $DIR/not-panic-safe-5.rs:6:14 | LL | fn assert() {} | ^^^^^^^^^^ required by this bound in `assert` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.