添加镜像:

修改存储库的命令和以前不太一样 以前：

composer config -g repos.packagist composer xxx

现在：

composer config -g repositories.foo composer xxx

腾讯：

composer config -g repositories.tencent composer https://mirrors.tencent.com/composer/

阿里：

composer config -g repositories.aliyun composer https://mirrors.aliyun.com/composer/

交通大学镜像，非全量

composer config -g repos.packagist composer https://packagist.mirrors.sjtug.sjtu.edu.cn

不太稳定：

composer config -g repo.packagist composer https://packagist.phpcomposer.com

另一个镜像：（已经停用：https://learnku.com/articles/30758）

composer config -g repo.packagist composer https://packagist.laravel-china.org