const {defineConfig} = require('@vue/cli-service')
module.exports = defineConfig({
    transpileDependencies: true,
    devServer: {
        port: 8081
    }
})

百度搜出来的博客说是vue-cli版本太低了,然后瞎升级了半天

  "devDependencies": {
    "@vue/cli-plugin-babel": "~4.5.15",
    "@vue/cli-plugin-router": "~4.5.15",
    "@vue/cli-service": "~4.5.15",
  }

给百度坑惨了,4.5的cli已经对应vue3了
正确解法还得看StackOverflow

如果不是用的vite,还是老写法