(define-record-type :rule-cand
  (make-rule-cand target prereqs up-to-date?-func build-func)
  is-rule-cand?
  (target rule-cand-target)
  (prereqs rule-cand-prereqs)
  (up-to-date?-func rule-cand-up-to-date?-func)
  (build-func rule-cand-build-func))