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(|| {
   |  __________-
LL | |         // Shouldn't suggest `move ||.as_ref()` here
LL | |         move || {
   | |         ^^^^^^^ move out of `var` occurs here
LL | |
LL | |             var = Some(NotCopyable);
   | |             ---
   | |             |
   | |             move occurs because `var` has type `Option<NotCopyable>`, which does not implement the `Copy` trait
   | |             move occurs due to use in closure
LL | |         }
LL | |     });
   | |_____- captured by this `FnMut` closure

error: aborting due to previous error

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