Thanks for the report, this is strange
It looks like for some reason, the label isn’t added to the outgoing examples correctly, which results in the task validation complaining that the incoming data doesn’t have the right format.
As a quick fix, you can either set "validate": false in your prodigy.json, or make the following edit in the textcat_eval function in recipes/textcat.py:
def add_label_to_stream(stream, label):
for eg in stream:
eg['label'] = label
yield eg
stream = get_stream(source, api, loader)
stream = add_label_to_stream(stream, label)