warning: unused variable: `old`
 --> $DIR/scope_callback_capture.rs:9:29
  |
9 |                 if let Some(old) = inner.take() {
  |                             ^^^ help: if this is intentional, prefix it with an underscore: `_old`
  |
  = note: `#[warn(unused_variables)]` on by default

error[E0521]: borrowed data escapes outside of closure
  --> $DIR/scope_callback_capture.rs:7:17
   |
5  |       lua.scope(|scope| {
   |                  -----
   |                  |
   |                  `scope` declared here, outside of the closure body
   |                  `scope` is a reference that is only valid in the closure body
6  |           let mut inner: Option<Table> = None;
7  |           let f = scope
   |  _________________^
8  | |             .create_function_mut(move |_, t: Table| {
9  | |                 if let Some(old) = inner.take() {
10 | |                     // Access old callback `Lua`.
...  |
13 | |                 Ok(())
14 | |             })?;
   | |______________^ `scope` escapes the closure body here
