how to library a window var

[406087475]

Version

5.0.8

Reproduction link

None

Environment info

windows

Steps to reproduce

最简单的初始化项目
vue create hello-world

调整main.js，输出aa函数
import { createApp } from 'vue'
import App from './App.vue'

createApp(App).mount('#app')

function aa () {
console.log(1)
}

export { aa }

调整vue.config.js，希望打包出window.Vue3
const { defineConfig } = require('@vue/cli-service')
module.exports = defineConfig({
filenameHashing: false,
transpileDependencies: true,
configureWebpack: {
output: {
library: Vue3,
libraryTarget: 'umd'
}
}
})

What is expected?

希望script标签引入打包后的文件，页面window.Vue3能使用

What is actually happening?

结果，window.Vue3 undefined