试图添加到这个问题：NVM Command Not Found，但是不能。
安装 nvm 后，我遇到了同样的问题，这是来自终端的日志：
Michael-iMac:~ michaels_imac$ curl https://raw.github.com/creationix/nvm/master/install.sh | sh
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 1202 100 1202 0 0 5759 0 --:--:-- --:--:-- --:--:-- 6829
=> NVM is already installed in /Users/michaels_imac/.nvm, trying to update
=>
Already up-to-date.
Michaels-iMac:~ michaels_imac$ nvm install 0.8
-bash: nvm: command not found