angular – 无法将浏览器连接到Karma服务器(永久页面加载)

业力日志：

17 07 2018 13:29:01.754:INFO [karma]: Karma v1.7.1 server started at http://0.0.0.0:9877/
17 07 2018 13:29:01.758:INFO [launcher]: Launching browser Chrome with unlimited concurrency
17 07 2018 13:29:01.773:INFO [launcher]: Starting browser Chrome

 10% building modules 1/3 modules 2 active …tsrafa-components-libsrcpolyfills.ts
 10% building modules 2/3 modules 1 active …tsrafa-components-libsrcpolyfills.ts
 75% basic chunk optimization EnsureChunkConditionsPlugin
 75% basic chunk optimization RemoveParentModulesPlugin
 88% hashing
 90% additional chunk assets processing
 92% after chunk asset optimization SourceMapDevToolPlugin main.js generate SourceMap
Waiting for a captured browser... To capture a browser open http://localhost:9877/

访问localhost：9877会导致永久加载.有时它按预期工作(业力开始和浏览器连接)但它有点随机.

也许有人知道发生了什么？

Karma配置：

module.exports = function (config) {
  config.set({
    basePath: '',frameworks: ['jasmine','@angular-devkit/build-angular'],plugins: [
      require('karma-jasmine'),require('karma-chrome-launcher'),require('karma-jasmine-html-reporter'),require('karma-coverage-istanbul-reporter'),require('@angular-devkit/build-angular/plugins/karma')
    ],client: {
      clearContext: false // leave Jasmine Spec Runner output visible in browser
    },coverageIstanbulReporter: {
      dir: require('path').join(__dirname,'../coverage'),reports: ['html','lcovonly'],fixWebpackSourcePaths: true
    },reporters: ['progress','kjhtml'],port: 9877,colors: true,logLevel: config.LOG_INFO,autoWatch: true,browsers: ['Chrome'],singleRun: false
  });
};

新的浏览器窗口：

建立连接：