OK, FWIW, I extracted the schema.py and fed it your schema with:

print(json.dumps(Schema.from_dict(json.loads(open("schema.json").read())).to_dict(), indent=2))

and it produced a schema. However, $refs were not followed, as it did things like:

"statuses": {
      "items": {},
      "type": [
        "array",
        "null"
      ]
    },

So it got statuses, but the items are blank.