So it seems the problem was actaully a user error, bcause OP used 'R instead of #\R for direction.

Failure messages in the Rove framework are another story. The framework is not easy to force it to cooperate, and while messages can be somewhat improved, they still won't be great, and most probably would not help in the OP's case.

I tried to solve the kata in CommonLisp and I think I run into similar issue. I will see what I can do, but I might be too much of a LISP noob to figure this out :D

Hey. I know/remember almost nothing about CommonLisp, but I checked your current solution and the way you're checking for equality seems wrong. Take a look at sample tests to see what form "dir" argument is of.

As for assertion messages, they indeed look weird, but the tests seem to pass the right values, so maybe it's just an issue of displaying incomplete/wrong error messages in assertions.

It fails, as the input is not the string "quijote" but a piece of text from that novel. Not a kata issue.