composer config -gl
阿里云
composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/
中国镜像
composer config -g repo.packagist composer https://packagist.phpcomposer.com
腾讯云
composer config -g repo.packagist composer https://mirrors.cloud.tencent.com/composer/
composer 忽略版本加载文件:composer install --ignore-platform-reqs