一、命令
1、国内镜像
composer config -g repo.packagist composer https://packagist.phpcomposer.com
2、重新生成autoload文件
composer dump/composer dumpautoload
二、composer自动加载原理
composer会根据每个包的composer.json里的autoload字段来需要自动加载的类的命名空间，注册到classLoader类中。被注册的类型有psr-0/psr-4/classmap/file
三、问题解决
1、PHP Fatal error: Uncaught exception 'ErrorException' with message 'proc_open(): fork failed - Cannot allocate memory' in phar. This could be happening because the VPS runs out of memory and has no Swap space enabled.
free -m total used free shared buffers cached Mem: 2048 357 1690 0 0 237 -/+ buffers/cache: 119 1928 Swap: 0 0 0 To enable the swap you can use for example: /bin/dd if=/dev/zero of=/var/swap.1 bs=1M count=1024 /sbin/mkswap /var/swap.1 /sbin/swapon /var/swap.1 You can make a permanent swap file following this tutorial.