[rendaw]

I hope you don't mind me plugging my thing here, but I had the 100% same problem and made aargvark (https://docs.rs/aargvark/latest/aargvark/). When I was using clap, every time I'd need to look up how to do X, or what combination of things I needed to put an enum here, or find out that this nesting of data types wasn't supported, etc.

It's still derive macro-based, but there's only one derive (`Aargvark`) rather than `Parser`, `Subcommand`, etc, and it can handle any data structure composition orthogonally (although crazy structures may result in fairly awkward command lines).