Error message
In the message, %s marks a value that the engine fills in when it raises the error.
The story
You gave labels to two arguments, and the labels contradict each other. Let's see how this works. Some builtins take two arguments of the same kind that play the same role, like the two ends of an interval. For those, order does not matter. Math dot randint of six and one means exactly the same as one and six: a random whole number between them. No labels needed, and rush is relaxed about the order. But if you add labels, you are making a claim about the order. Writing min colon six, max colon one says that the minimum is six and the maximum is one. And no interval has a minimum bigger than its maximum. That claim is false, and rush refuses only that. The rule is simple: if you force a wrong label, you get an error. If you leave the labels out, you get the natural behavior. The first slot shows the labels as you wrote them, and the second shows what to write instead. Either swap the values to match the labels, or drop the labels altogether.
Text from the Rush engine's error catalogue.