How to Install CoffeeScript

Install nvm and Node.js, then run npm install -g coffee-script to get CoffeeScript up and running.

How to Fix "You have $NVM_DIR set to "/Users/yourname/.nvm", but that directory does not exist."

Clearing the NVM_DIR environment variable to get past a failing nvm install script.

Update nvm version | nvm バージョンアップデート

Running the official nvm manual upgrade shell script to update nvm itself.