javascript - .Vue文件中无法编译<router-view>，Unknown custom component-PHP中文网问答

webpack.config.js

var webpack=require("webpack");

module.exports={
    entry: {
        index:'./frontend/index',
        // vendor:['vue','vuex','vue-router']
    },
    output:{
        path:'./build',
        filename:'[name].min.js',
        publicPath:'/build/',
        // chunkFilename:'[id].[chunkhash:5].chunk.js'
    },
    module:{
        loaders:[
            {
                test:/\.js[x]?$/,
                loader:'babel',
                exclude:/node_modules/,
                plugins:['transform-time']
            },
            {
                test:/\.css$/,
                loader:'style!css'
            },
            {
                test:/\.(eot|svg|ttf|woff|woff2)(\?\S*)$/,
                loader:'file-loader'
            },
            {
                test:/\.(png|jpe?g|svg|gif)(\?\S*)?$/,
                loader:'file-loader',
                query:{
                    name:'[name].[ext]?[hash]'
                }
            },
            {
                test:/\.vue$/,
                loader:'vue'
            }
        ]
    },
    resolve:{
        extensions:['','.js','.jsx']
    },
    plugins:[
        // new webpack.optimize.CommonsChunkPlugin('vendor','commons.js')
    ]
}

App.vue

<template>
    <p class="app">
        <Header></Header>
        <p class="menuBox fl">
        </p>
        <p class="mainBox">
            <p class="main">
                <transition>
                    <router-view></router-view>
                </transition>
            </p>
        </p>
    </p>
</template>
<style scoped>
</style>
<script>
    import Header from "./Header/Header.vue";

    export default{
        data(){
            return{
                menu:[
                    {
                        id:0,
                        linkName:"课程介绍",
                        path:'/a'
                    },
                    {
                        id:1,
                        linkName:"作业列表",
                        path:'/b'
                    },
                ]
            }
        },
        components:{
            Header
        }
    }
</script>

routes

import Vue from "vue/dist/vue.min";
import VueRouter from "vue-router";

Vue.use(VueRouter);
import App from "../components/App.vue";

const routes=[
    {
        path:'/',
        component:App,
        children:[
            {
                path:'/test',
                component:App
            }
        ]
    },
]

const router=new VueRouter({
    routes
});

export default router;

入口index.js

import Vue from "vue/dist/vue.min";
import VueResource from "vue-resource";
import VueHead from "vue-head";
import ElementUI from "element-ui";
import 'element-ui/lib/theme-default/index.css';
import router from "./routes";
import store from "./vuex";

Vue.use(VueResource);
Vue.use(VueHead);
Vue.use(ElementUI);

const app=new Vue({
    router,
}).$mount('#App');

运行命令webpack-dev-server --hot --inline --port 8080后，根路由系统正常，但App.vue中的<router-view>则失效，报错:

但如果运行webpack -p,并跑在node服务器上，则执行正常。感觉像是webpack-dev-server的配置问题，求各位大大解答看我这样配是不是有问题。

ps:所有依赖均已升级至最新版本。