问如何在buildozer.spec python kivy中包含mp3文件

EN

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.label import Label
from kivy.core.audio import SoundLoader
from kivy.graphics.context_instructions import Color


class TestApp(App):
    def build(self):
        fl = FloatLayout()
        try:
            sound = SoundLoader.load('magic.mp3')
            if sound:
                print("Sound found at %s" % sound.source)
                print("Sound is %.3f seconds" % sound.length)
                fl.add_widget(Label(text=str("Sound found at %s" % sound.source), pos=(0, 0), font_size=(40)))
                sound.play()
        except Exception as error:
            fl.add_widget(Label(text=str(error), pos=(0, 0), font_size=(40)))
        return fl


if __name__ == "__main__":
    TestApp().run()

# (list) Source files to include (let empty to include all the files)
source.include_exts = py,png,jpg,kv,atlas,mp3

# (list) List of inclusions using pattern matching
source.include_patterns = assets/*,magic/*.mp3

'NoneType' object has no attribute 'source'