This sounds like really catastrophically bad advice. "Source" (the dot command) tries to load something into your shell, it is supposed to take a shell language (bash, zsh, etc) language file, you might see this as ". something.sh" usually.
When you run this with a Ruby file, most of the content in the `capify` Ruby file has no meaning to the shell. However restarting the terminal should have cleared any ill effects, unless this ". capify" is in a startup file, such as .bashrc, or .profile or similar in your user's home directory (either side of the server)
There might be a gross misunderstanding here too, as the "cap" and "capify" commands are never intended to run on your server, but on your workstation and connect out to your servers over SSH.