Any of those help So the answer is, there isn't any! Intentionally! And once I read the reasoning, it actually made sense. Though it is a bummer I can't do local nginx installs to people's $HOME dir, but I can live with that. See this stackoverflow answer:
Why does my php HOME environment variable not match the HOME variable in my linux bash shell?
like below fixes the issue R startup is somewhat complicated, but it is pretty well documented. The usual starting place is help("Startup"). The answer to your question is not documented there, but you will find this clue in the See also section: