先设置 Composer 的下载源,也是镜像地址,在命令行窗口或控制台 输入
composer config -g repo.packagist composer [https://packagist.phpcomposer.com](https://packagist.phpcomposer.com)
如果 phpcomposer 镜像有问题,可以换下面的
composer config -g repo.packagist composer [https://packagist.laravel-china.org](https://packagist.laravel-china.org)