The Mink testsuite currently does not require any specific message for an exception thrown when calling the code on an invalid XPath. Requiring a specific message would make the implementation more complex in all drivers by forbidding to have the DriverException coming from a more generic place (like here thanks to #73).

I haven't verified the message by checking what happens locally, as Zombie does not install on Windows (the issue being actually jsdom) and I have no VM yet to test it.