(defparameter *a* nil)
(push (cons "a" "apple") *a*) ; => (("a" . "apple"))

;; This macro is incorrect but I want to understand its incorrectness.
(defmacro push-key-value (key value alist)
  (push (cons key value) alist))

(push-key-value "a" "apple" *a*)
(macroexpand-1 '(push-key-value "a" "apple" *a*)) ; => (("a" . "apple") . *A*), T

;; I was expecting the expansion to be (("a" . "apple")).