use vitejs: reactive cannot define const in script setup

[DebugIsFalse]

Describe the bug

when i use setup in script, will not work
template

<div class="attrs-item">
    <div class="todo-wrapper">
        <div class="todo-write">
            <input type="text" v-model="todoValue" @keypress.enter="addToDoList">
        </div>
        <div class="todolist-drop">
            <div class="todolist-drop-item" v-for="it in todoList" :key="it.id">
                {{it.value}}
            </div>
        </div>
    </div>
</div>

javascript

<script lang="ts" setup>
import { reactive, ref, unref} from 'vue';
interface todoItem {
    status: number,
    value: any,
    id: number
}
const todoValue = ref();
const todoList:Array<todoItem> = reactive([]);
const addToDoList = function(){
    const item = {
        status: 1,
        id: Math.random(),
        value: unref(todoValue)
    }
    todoList.push(item);
    console.log(todoList, '===todoList')
}
</script>

Reproduction

it work in 2.0.0-beta.66
if change
const todoList:Array<todoItem> = reactive([]);
to
let todoList:Array<todoItem> = reactive([]);
the code will run;
and if the code run in setup function also run normal

System Info

• vite version: 2.0.0-beta.66
• Operating System: mac OS
• Node version: v12.18.2
• Package manager (npm/yarn/pnpm) and version:

Logs (Optional if provided reproduction)

[Vue warn]: Unhandled error during execution of scheduler flush. This is likely a Vue internals bug. Please open an issue at https://new-issue.vuejs.org/?repo=vuejs/vue-next
at <ToDoList onVnodeUnmounted=fn ref=Ref< {} > >
at
at
[Vue error]: Uncaught (in promise) TypeError: Cannot read property 'type' of undefined