Anyway, I skimmed the file for you this time, and basically you're either correct or wrong, depending on your definition of "error checking." The code handles error conditions by aborting the process. Seeing as it's a standalone CLI program and not a library meant for reuse, safely shutting down with a meaningful message sounds like fair game to me.
You can leave the snide comments about “Rust culture” (whatever that is) out next time.
The way a language's community handles errors and how the language itself handles errors are different things, sure, but they're not independent of each other.
That said, OP's snark against Rust is completely unmerited, and they can take my `impl From<OtherErr> for MyErr` from my cold dead hands.