Sorry about that – this error is related to the msgpack dependency in spaCy and started occurring this morning when a new msgpack version was released. You can find more details on this on the spaCy issue tracker. For now, a simple fix is to downgrade msgpack-python:
Just released spaCy v2.0.9 which includes the explicit version pin, and prevents the library from installing the latest update of msgpack-python that caused this problem. You should be able to simply upgrade spaCy in your Prodigy environment:
pip install -U spacy
Prodigy v1.3.0 is pinned to spacy>=2.0.8,<2.1.0, so it should now install v2.0.9 by default.
(This was a nice reminder to always pin dependencies, and always use explicit pins for versions < 1.0 that don’t ensure backwards compatibility.)