Error propagation
We need to add error propagation to this system.
Kinds of errors that are propagated:
- opaque "internal" errors. Something went wrong, but we aren't going to tell you what it was. Most exceptions that happen during message processing will result in propagating errors of this type.
- "broadcast" errors. These are errors raised with raise-broadcast-error and always have a tag (a symbol) and then may have whatever other arguments, which can be propagated.
- "not found" errors. The 404 of Goblins! You tried to message an actor, but no such actor is registered with the system.