error[E0507]: cannot move out of `var`, a captured variable in an `FnMut` closure
  --> $DIR/option-content-move2.rs:9:9
   |
LL |     let mut var = None;
   |         ------- captured outer variable
LL |     func(|| {
   |          -- captured by this `FnMut` closure
LL |         // Shouldn't suggest `move ||.as_ref()` here
LL |         move || {
   |         ^^^^^^^ move out of `var` occurs here
LL |
LL |             var = Some(NotCopyable);
   |             ---
   |             |
   |             variable moved due to use in closure
   |             move occurs because `var` has type `Option<NotCopyable>`, which does not implement the `Copy` trait

error: aborting due to previous error

For more information about this error, try `rustc --explain E0507`.