error[E0277]: the type `UnsafeCell<()>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
   --> $DIR/ref_nounwindsafe.rs:8:5
    |
8   |     catch_unwind(move || table.set("a", "b").unwrap());
    |     ^^^^^^^^^^^^ `UnsafeCell<()>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
   ::: $RUST/std/src/panic.rs
    |
    | pub fn catch_unwind<F: FnOnce() -> R + UnwindSafe, R>(f: F) -> Result<R> {
    |                                        ---------- required by this bound in `catch_unwind`
    |
    = help: within `Lua`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<()>`
    = note: required because it appears within the type `PhantomData<UnsafeCell<()>>`
    = note: required because it appears within the type `Lua`
    = note: required because of the requirements on the impl of `UnwindSafe` for `&Lua`
    = note: required because it appears within the type `mlua::types::LuaRef<'_>`
    = note: required because it appears within the type `LuaTable<'_>`
    = note: required because it appears within the type `[closure@$DIR/tests/compile/ref_nounwindsafe.rs:8:18: 8:54]`