FIND_PROGRAM(STACK_EXECUTABLE stack)
SET(STACK_FOUND FALSE)
IF (STACK_EXECUTABLE)
SET(STACK_FOUND TRUE)
SET(MESSAGE_STATUS "Stack found.")
ELSE (STACK_EXECUTABLE)
SET(MESSAGE_STATUS "Stack was not found. Haskell bindings will not be built.")
ENDIF (STACK_EXECUTABLE)
MESSAGE(STATUS ${MESSAGE_STATUS})