DB switches from Custom back to SQLite

I don't think that custom DBs work as documented across a couple of different dimensions, but for whoever comes after, I got it working by setting the default DB via prodigy.json and adding the DB to the databases registry using:

from prodigy.util import registry
prodigy.databases.register("mongodb", func=AnnotationsDatabase())

This is a bit confusing because register is a decorator elsewhere but func here accepts a class instantiation.

prodigy.json now includes:

  "db": "mongodb"

It now seems to work as expected.

This post was critical information that I couldn't get to by looking at the prodigy source because prodigy.util is compiled now.