Wrong warning message about default export

[a1mersnow]

Version

3.0.0-rc.2

Reproduction link

https://github.com/aimergenge/reproduction-for-vue3

Steps to reproduce

1. clone the reproduction repo
2. use cd move into it
3. yarn
4. yarn dev
5. edit HelloWorld.vue, save
6. ctrl z/cmd z, save

What is expected?

Nothing should be warned

What is actually happening?

There is a warning said:

Default export is already declared in normal <script>.

12 |  <script setup="props">
13 |  import { defineComponent, onMounted, toRef, ref, watchEffect, computed } from "vue";
14 |  
   |   ^
15 |  export default defineComponent({
   |  ^^^^^^^^^^^^^^
16 |    name: 'HelloWorld'

[posva]

There is no warning...

[a1mersnow]

@posva Have you followed my steps to reproduce?
Especially step 5 & 6

Try some times you will see it……

[posva]

Now I managed to reproduce it, it only happens when doing the undo action, not when changing the name to something else