Add some small test code for tracking down this list bug

crates/gpui/src/window.rs

@@ -1716,6 +1716,7 @@ impl<'a> WindowContext<'a> {
             .mouse_listeners
             .remove(&event.type_id())
         {
+            dbg!(handlers.len());
             // Because handlers may add other handlers, we sort every time.
             handlers.sort_by(|(a, _, _), (b, _, _)| a.cmp(b));