A bit of feedback to the author: I cringe really, really hard when I see things like:

  #[derive(Debug)]
  enum RispErr {
    Reason(String),
  }

One of the beauties of Rust's type system is that you can combine meaningful error types with the From trait to build zero-effort error handling. When you turn every error into a String, you lose information that future programmers (including yourself!) will be glad to have. I know it can be a little bit painful to get used to, but once you do, meaningful error handling will be at your fingertips.

To be helpful to readers of this comment and not just critical of the author, I recommend you don't overthink your error types when you're first starting to write your program. Think of the contents of the enum like a "scratchpad" where you list every failure mode you've encountered so far. While you're still developing, you can greedily match on every variant in your match statements, and it's fine. As you do this, you'll begin to notice themes that will inform the eventual refactor. Best of all, once you do refactor, you won't have to re-understand your code to tease out the various kinds of failures - you'll already have a list of them!