If the src is empty list, it will crash at:
IndexError: list index out of range:
File "/home/xxx/src/SConstruct", line 39:
objs = PrepareBuilding(env, RTT_ROOT, has_libcpu=True)
...
File "/home/xxx/src/drivers/SConscript", line 12:
SrcRemove(src, src_need_remove)
File "/home/rt-thread-stable/tools/building.py", line 496:
if type(src[0]) == type('str'):
d33df46f19