Maintaining Environment Variables with sudo

Especially useful if you need to use proxies. E.g., this will fail since
the sudo user doesn’t know about the https_proxy variable.

sudo curl -L | bash -s stable --ruby

The solution is to visudo, find this

Defaults env_reset 

and add this for each variable you want available.

Defaults env_keep += "variable1 variable2"

In the case of proxies,

Defaults env_keep += "http_proxy https_proxy ftp_proxy"