composer安装插件出现内存不足问题

近期用命令composer require phpoffice/phpspreadsheet安装phpspreadsheet时出现内存不足问题，出现以下错误：

The following exception is caused by a lack of memory or swap, or not having swap configured

用如下方法完美解决：

sudo /bin/dd if=/dev/zero of=/var/swap.1 bs=1M count=1024  
sudo /sbin/mkswap /var/swap.1
sudo /sbin/swapon /var/swap.1