The DEFINE-CONSTANT that comes with Alexandria causes "deleting unreachable code" style-warnings in SBCL; I couldn't understand what caused them, so Nikodemus as group-local SBCL expert may want to take a look at it; either SBCL is way smarter than me, or there's a bug hiding somewhere. Anyway, my patch moves most of the macroexpansion of DEFINE-CONSTANT to its own function which is prettier anyway. This also makes the warnings go away. -T.