Compile error with a single c-define

[refrogerator]

Trying to write some raylib bindings i have discovered that having a single c-define in your library generates a compiler error:

code:

;; raylib/main.sld
(define-library (raylib main)
  (export init-window)
  (import (scheme base)
          (scheme write)
          (cyclone foreign))
  (include-c-header "<raylib.h>")
  (c-linker-options "-lraylib")
  (begin
    (c-define init-window c-void "InitWindow" int int string)))

error:

Error: (Unhandled expansion (define-c init-window (void *data, int argc, closure _, object k , object arg_738, object arg_7315, object arg_7322) Cyc_check_fixnum(data,arg_738);Cyc_check_fixnum(data,arg_7315);Cyc_check_str(data,arg_7322);InitWindow(obj_obj2int(arg_738),obj_obj2int(arg_7315),string_str(arg_7322));return_closcall1(data, k, Cyc_VOID);)):

adding something else to the library, for example (define test 2), makes the error go away