ng add @angular/pwa - 无法读取未定义的属性'length'

Question

我正在尝试将PWA功能添加到Angular 8项目中(使用ng new生成(。

ng add @angular/pwa --project projectname

得到错误：

Installing packages for tooling via npm.
+ @angular/pwa@0.803.19
added 5 packages from 2 contributors and audited 18965 packages in 6.091s
found 0 vulnerabilities
Installed packages for tooling via npm.
Cannot read property 'length' of undefined

伙计们有什么想法吗？

(其余的ng命令运行良好，我可以服务、构建生产广告等(

Answer 1

谁会想到呢？！

经过数小时的尝试，结果发现原因是src/app/app.module.ts:中的这行代码

import {environment as env} from '../environments/environment';

如果导入不带别名的environment，则一切正常。奇怪的

ng version:

Angular CLI: 8.3.19
Node: 10.16.3
OS: darwin x64
Angular: 8.2.14