所有项目都会使用该镜像地址：

composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/

取消配置：

composer config -g --unsetrepos.packagist

项目配置

仅修改当前工程配置，仅当前工程可使用该镜像地址：

composer config repo.packagist composer https://mirrors.aliyun.com/composer/

取消配置：

composer config --unsetrepos.packagist

调试

composer 命令增加 -vvv 可输出详细的信息，命令如下：

composer -vvvrequirealibabacloud/sdk