If you are using OS X, you might have to create your .bash_profile file before running the installation command. That did it for me.
Create the profile file
touch ~/.bash_profile
Re-run the install and you'll see a relevant line in the output this time.
=> Appending source string to /Users/{username}/.bash_profile
Reload your profile (or close/re-open the Terminal window).
. ~/.bash_profile