Only the root of the call stack, fn main, should be able to return anything to the user. Everything else should return errors to their callers through the norma

Only the root of the call stack, fn main, should be able to return anything to the user. Everything else should return errors to their callers through the normal return mechanisms. Anything else, anything that introduces the possibility of shadow control flow, makes it basically impossible to maintain a working mental model of nontrivial programs.