Error message
In the message, %s marks a value that the engine fills in when it raises the error.
The story
One of the lines in your requires list is not written the way rush reads it. Let's see what a good line looks like. A requires item reads like the header of a function: the project name, a dot, the module, a dot, the function name, then square brackets with each parameter and its rule, then an arrow, and the rule of the result. Written that way, the line produces exactly the same fingerprint as the real function in the other project, and rush can compare the two. Now, what if the item is only a function name with no dots? Or has no parameter list? Or has extra words after the contract? Then it states no contract at all, and there is nothing to compare, so rush refuses by name and shows you the line. Think of it as a signature on a form: if the form is incomplete, it cannot be checked. The fix is to write the full name and the full contract, exactly as the peer declares them. Copy the header from the peer's source, drop it into requires, and the check will run.
Text from the Rush engine's error catalogue.