So I do the following:
- create (or import) some cards, let's say 30 of them and put them in a category
- create a new test, set selection to repetition-spaced
- check "limit new cards" to maximum unlearned 5
- set "card is learned if" to "correct in row" 3
- start test, get presented 5 cards as expected
- since cards are new, fail all 5 cards
- begin another session of the same test
- "No more cards are due for review right now."