I did this with a moderate sized cli tool; it was really good to be able to see effectively every error state you could have at the top level of the program. S

I did this with a moderate sized cli tool; it was really good to be able to see effectively every error state you could have at the top level of the program. Something I didn't find an ergonomic solution to though was pulling out common errors; I wanted to say, pull out any std::io errors that occurred at the top level, but all I found was to match and expand every error case to pull them out. I considered maybe a derive/trait based approach would work, but it was too big a hammer for that project.