# Pastebin wRM3KGMG
(advice-add 'flycheck-define-command-checker :filter-args
            (lambda (args)
              (if (eq 'python-pyre (car args))
                  (cl-labels ((go (r)
                                (cond
                                 ((eq r nil) nil)
                                 ((eq (car r) :command)
                                  (let ((command (cadr r)))
                                    (setf (nth 1 command) "@pyre@/bin/pyre")
                                    `(:command ,command ,@(cddr r))))
                                 (t (cons (car r) (go (cdr r)))))))
                    (go args))
                args)))