[iterate-devel] Bug with (collect :at :beginning)

When collecting values into a list, if the first value collected uses (collect val :at :beginning), and a subsequent value does not use the ":at :beginning" clause, then an error will occur: "The value nil is not of type cons". The following reproduces this error: (iterate (for i from 1 to 10) (if (oddp i) (collect i :at :beginning) (collect i)))