scons --target=iar 运行报错TypeError

# scons --target=iar
scons: Reading SConscript files ...
TypeError: can only concatenate deque (not "list") to deque:
  File "E:\rt-thread\rt-thread-v4.1.0\bsp\stm32\stm32f4xx-lift-rtthread\SConstruct", line 60:
    DoBuilding(TARGET, objs)
  File "E:\rt-thread\rt-thread-v4.1.0\tools\building.py", line 870:
    local_group(group, objects)
  File "E:\rt-thread\rt-thread-v4.1.0\tools\building.py", line 828:
    CPPDEFINES = Env.get('CPPDEFINES', ['']) + group.get('LOCAL_CPPDEFINES', [''])