composer安裝插件出現內存不足問題

近期用命令composer require phpoffice/phpspreadsheet安裝phpspreadsheet時出現內存不足問題，出現以下錯誤：

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

用如下方法完美解決：

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