For some reason, `tracing::instrument` proc_macro doesn't always print
elements specified via `fields()` or even show that it's impossible
(e.g. there's no Display impl).
Work around this using the `?foo` notation.
Before:
2023-04-03T14:48:06.017504Z INFO handle_client🤝 received SslRequest
After:
2023-04-03T14:51:24.424176Z INFO handle_client{session_id=7bd07be8-3462-404e-8ccc-0a5332bf3ace}🤝 received SslRequest