尝试运行（ng serve），但它一直要求更新@ angular / cli，但（ng update @ angular / cli）不起作用

Question

我尝试使用ng serve运行我的角度项目，但是显示此错误：

The Angular CLI configuration format has been changed, and your existing
configuration can be updated automatically by running the following command:

    ng update @angular/cli

我运行相同的命令，然后当我尝试运行ng serve时，它一次又一次显示此错误。

以下是我终端中的输出：

$ ng serve

The Angular CLI configuration format has been changed, and your existing
configuration can be updated automatically by running the following command: 

    ng update @angular/cli

$ ng update @angular/cli

$ ng serve  

The Angular CLI configuration format has been changed, and your existing
configuration can be updated automatically by running the following command:

    ng update @angular/cli

这也是Angular配置：

Angular CLI: 6.2.3
Node: 10.9.0
OS: darwin x64
Angular: 6.1.9
@angular-devkit/architect         0.8.3
@angular-devkit/build-angular     0.8.3
@angular-devkit/build-optimizer   0.8.3
@angular-devkit/build-webpack     0.8.3
@angular-devkit/core              0.8.3
@angular-devkit/schematics        0.8.3
@angular/cli                      6.2.3
@ngtools/webpack                  6.2.3
@schematics/angular               0.8.3