Angular EmptyError:no elements in sequence

今天重构代码，发现控制台一直报错：

EmptyError:no elements in sequence

const routes: Routes = [
  { path: '', redirectTo: 'home', pathMatch: 'full' },
  {
    path: 'home',
    component: HomeComponent,
    children: [
      {
        path: '',
        loadChildren: () => import('xxx/pages.module').then(m => m.PagesModule)
      }
    ],
    canActivate: [AppGuard]
  }
];

@NgModule({
  declarations: [
    HomeComponent,
  ],
  imports: [
    PagesModule // 删掉
  ]
})
export class HomeModule { }

百思不解，排查了半天，发现是 routes: Routes = [] 里 loadChildren 的模块在当前的 module 里也import 了，删除掉 import 里重复的 loadChildren module 就好了!