Traversing though the error tree is the worst case where the structured error has been bubbled up through layers until the one who are able to recover from it.
let data = serialize(&doc)
.or_raise(|| StorageError::permanent("serialization failed"))?;
The closure in `or_raise` should take the error from `serialize(&doc)` as an argument and save the actionable details. It makes sense to have an "outermost error" when you're talking about a context trace that provides information to humans, but an error which a machine responds to should be flat & statically matchable.
Something like this:
let data = serialize(&doc)
.or_raise(|e| Exn::with_message(
"serialization failed",
StorageError::fromInner(e)))?;