[Openmcl-devel] Error with ccl:rlet

[idan mandelbaum]

I am trying to do the following:
(let ((x 3))  (ccl:rlet ((my-array (:array :address x)))))
basically use a variable for the array length. I get the following error:

First dimension is not a non-negative fixnum or NIL: X
   [Condition of type SIMPLE-ERROR]

I tried to force x to be fixnum:
(let ((x 3))  (declare (fixnum x)) (ccl:rlet ((my-array (:array :address x)))))
I still get the same error. What am i doing wrong?

Thanks
Idan