解决composer update zlib_decode错误问题

今天在一个服务器上安装了一个walle-web的项目，要使用composer来安装
由于服务器没有安装composer，先安装一下

centos安装composer

curl -sS http://getcomposer.org/installer | php
mv composer.phar /usr/local/bin/composer

composer update错误

在我更想这个项目的时候发现提示如下错误信息

Failed to decode response: zlib_decode(): data error
Retrying with degraded mode, check https://getcomposer.org/doc/articles/troubleshooting.md#degraded-mode for more info
Your requirements could not be resolved to an installable set of packages.

解决方法

执行命令

composer self-update