title: npm run build doesn't work."Opening index.html over file:// won't work."
body: <p>I'm trying to use Vue(v2) to build a single page application. Running the command <code>npm run build</code> doesn't work; I don't find a static file created in my folder. Although I don't get any error message, I see this in the command line after executing <code>npm run build</code>:</p>
  
  <blockquote>
    <p>Build complete. Tip: built files are meant to be served over an HTTP server. Opening index.html over file:// won't work.</p>
  </blockquote>
  
  <p>The content of my <code>build/build.js</code> file (which is the script that <code>npm run build</code> executes) is as follows:</p>
  
  <pre><code>require('./check-versions')()
  process.env.NODE_ENV = 'production'
  
  var ora = require('ora')
  var rm = require('rimraf')
  var path = require('path')
  var chalk = require('chalk')
  var webpack = require('webpack')
  var config = require('../config')
  var webpackConfig = require('./webpack.prod.conf')
  
  var spinner = ora('building for production...')
  spinner.start()
  
  rm(path.join(config.build.assetsRoot, config.build.assetsSubDirectory), err =&gt; {
    if (err) throw err
    webpack(webpackConfig, function (err, stats) {
      spinner.stop()
      if (err) throw err
      process.stdout.write(stats.toString({
        colors: true,
        modules: false,
        children: false,
        chunks: false,
        chunkModules: false
      }) + '\n\n')
  
      if (stats.hasErrors()) {
        console.log(chalk.red('  Build failed with errors.\n'))
        process.exit(1)
      }
  
      console.log(chalk.cyan('  Build complete.\n'))
      console.log(chalk.yellow(
        '  Tip: built files are meant to be served over an HTTP server.\n' +
        '  Opening index.html over file:// won\'t work.\n'
      ))
    })
  })
  </code></pre>
  
  <p>The content of my webpack.prod.conf.js file:</p>
  
  <pre><code>var path = require('path')
  var utils = require('./utils')
  var webpack = require('webpack')
  var config = require('../config')
  var merge = require('webpack-merge')
  var baseWebpackConfig = require('./webpack.base.conf')
  var CopyWebpackPlugin = require('copy-webpack-plugin')
  var HtmlWebpackPlugin = require('html-webpack-plugin')
  var ExtractTextPlugin = require('extract-text-webpack-plugin')
  var OptimizeCSSPlugin = require('optimize-css-assets-webpack-plugin')
  
  var env = process.env.NODE_ENV === 'testing'
    ? require('../config/test.env')
    : config.build.env
  
  var webpackConfig = merge(baseWebpackConfig, {
    module: {
      rules: utils.styleLoaders({
        sourceMap: config.build.productionSourceMap,
        extract: true
      })
    },
    devtool: config.build.productionSourceMap ? '#source-map' : false,
    output: {
      path: config.build.assetsRoot,
      filename: utils.assetsPath('js/[name].[chunkhash].js'),
      chunkFilename: utils.assetsPath('js/[id].[chunkhash].js')
    },
    plugins: [
      // http://vuejs.github.io/vue-loader/en/workflow/production.html
      new webpack.DefinePlugin({
        'process.env': env
      }),
      new webpack.optimize.UglifyJsPlugin({
        compress: {
          warnings: false
        },
        sourceMap: true
      }),
      // extract css into its own file
      new ExtractTextPlugin({
        filename: utils.assetsPath('css/[name].[contenthash].css')
      }),
  // Compress extracted CSS. We are using this plugin so that possible
  // duplicated CSS from different components can be deduped.
      new OptimizeCSSPlugin({
        cssProcessorOptions: {
          safe: true
        }
      }),
  // generate dist index.html with correct asset hash for caching.
  // you can customize output by editing /index.html
  // see https://github.com/ampedandwired/html-webpack-plugin
      new HtmlWebpackPlugin({
        filename: process.env.NODE_ENV === 'testing'
          ? 'index.html'
          : config.build.index,
        template: 'index.html',
        inject: true,
        minify: {
          removeComments: true,
          collapseWhitespace: true,
          removeAttributeQuotes: true
      // more options:
      // https://github.com/kangax/html-minifier#options-quick-reference
        },
    // necessary to consistently work with multiple chunks via CommonsChunkPlugin
            chunksSortMode: 'dependency'
      }),
  // keep module.id stable when vender modules does not change
      new webpack.HashedModuleIdsPlugin(),
  // split vendor js into its own file
      new webpack.optimize.CommonsChunkPlugin({
        name: 'vendor',
        minChunks: function (module, count) {
      // any required modules inside node_modules are extracted to vendor
          return (
            module.resource &amp;&amp;
            /\.js$/.test(module.resource) &amp;&amp;
            module.resource.indexOf(
              path.join(__dirname, '../node_modules')
            ) === 0
          )
        }
      }),
  // extract webpack runtime and module manifest to its own file in order to
  // prevent vendor hash from being updated whenever app bundle is updated
      new webpack.optimize.CommonsChunkPlugin({
        name: 'manifest',
        chunks: ['vendor']
      }),
  // copy custom static assets
      new CopyWebpackPlugin([
        {
          from: path.resolve(__dirname, '../static'),
          to: config.build.assetsSubDirectory,
          ignore: ['.*']
        }
      ])
    ]
  })
  
  if (config.build.productionGzip) {
    var CompressionWebpackPlugin = require('compression-webpack-plugin')
  
    webpackConfig.plugins.push(
      new CompressionWebpackPlugin({
        asset: '[path].gz[query]',
        algorithm: 'gzip',
        test: new RegExp(
          '\\.(' +
          config.build.productionGzipExtensions.join('|') +
          ')$'
        ),
        threshold: 10240,
        minRatio: 0.8
      })
    )
  }
  
  if (config.build.bundleAnalyzerReport) {
     var BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin
    webpackConfig.plugins.push(new BundleAnalyzerPlugin())
  }
  
  module.exports = webpackConfig
  </code></pre>
  
  <p>What should I do about it?</p>