The following code can't be compiled on SBCL (0.9.11 on FreeBSD/x86,
0.9.11.8 on FreeBSD/x86, and 0.9.11 on Linux/x86).
(defun foo (n a)
(declare (optimize (speed 3)))
(if (= n 0) 0 (foo (1- n) a)))
I attached a full log of error messages and back trace.
If the optimization level is changed to (optimize (speed 2)), the error
does not occur.