### Version 3.0.0-alpha.0 ### Reproduction link [https://jsfiddle.net/bn08c9rL/2/](https://jsfiddle.net/bn08c9rL/2/) ### Steps to reproduce 1. Create a reactive() object. 2. Create a reactive() set. 3. add() the reactive object to the set. 4. Attempt to delete() the reactive object from the set. The item is not deleted. ### What is expected? The item should be deleted from the set. ### What is actually happening? The item is not deleted from the set. <!-- generated by vue-issues. DO NOT REMOVE -->