Приложение Kivy работает на рабочем столе, но не на Android

Я попытался создать программу для чтения PDF-файлов с преобразованием текста в речь, которая отлично работает на моем Ubuntu 14.04 LTS, и при компиляции с использованием buildozer также не возникает ошибок. Но приложение для Android запускается и закрывается без отображения при выборе. Вот приложения main.py и buildozer.spec, а также журнал ошибок с помощью logcat.

main.py-

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
import os
from plyer import notification, tts
#setup graphics
from kivy.config import Config
Config.set('graphics','resizable',0)
from kivy.lang import Builder
from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.converter import TextConverter
from pdfminer.layout import LAParams
from pdfminer.pdfpage import PDFPage
from cStringIO import StringIO


Builder.load_string("""
<MyWidget>:
    id: my_widget

    FileChooserListView:
        id: filechooser
        on_selection: my_widget.talk(filechooser.selection)
""")

class MyWidget(BoxLayout):
    def open(self, path, filename):

        with open(os.path.join(path, filename[0])) as f:
            print f.read()

    def selected(self, filename):
        print "selected: %s" % filename[0]

    def notify(self):
        try:
            #this notification will pop up on ubuntu as well!'
            notification.notify(title="Kivy  Notification",message="Plyer Up and Running!",
        app_name="kivy_test",app_icon="icon.png",timeout=10)
        except:
            print 'error notifiying'


    def talk(self,file_path):
        try:
            tts.speak(message=self.convert_pdf_to_txt(file_path[0]))
        except:
            print 'cant talk'


    def convert_pdf_to_txt(self,path):
        rsrcmgr = PDFResourceManager()
        retstr = StringIO()
        codec = 'utf-8'
        laparams = LAParams()
        device = TextConverter(rsrcmgr, retstr, codec=codec, laparams=laparams)
        fp = file(path, 'rb')
        interpreter = PDFPageInterpreter(rsrcmgr, device)
        password = ""
        maxpages = 0
        caching = True
        pagenos=set()

        for page in PDFPage.get_pages(fp, pagenos, maxpages=maxpages,                                                                                         password=password,caching=caching, check_extractable=True):
            interpreter.process_page(page)

            text = retstr.getvalue()

        fp.close()
        device.close()
        retstr.close()
        return text



class MyApp(App):
     def build(self):
        return MyWidget()

if __name__ == '__main__':
    MyApp().run()

А вот и файл спецификации

buildozer.spec-

[app]

# (str) Title of your application
title = My First Application

# (str) Package name
package.name = MyApp

# (str) Package domain (needed for android/ios packaging)
package.domain = org.test

# (str) Source code where the main.py live
source.dir = .

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

# (list) Source files to exclude (let empty to not exclude anything)
#source.exclude_exts = spec

# (list) List of directory to exclude (let empty to not exclude anything)
#source.exclude_dirs = tests, bin

# (list) List of exclusions using pattern matching
#source.exclude_patterns = license,images/*/*.jpg

# (str) Application versioning (method 1)
#version.regex = __version__ = ['"](.*)['"]
#version.filename = %(source.dir)s/main.py

# (str) Application versioning (method 2)
version = 1.2.0

# (list) Application requirements
# comma seperated e.g. requirements = sqlite3,kivy
requirements = kivy,plyer,pdfminer

# (str) Custom source folders for requirements
# Sets custom source for any requirements with recipes
# requirements.source.kivy = ../../kivy

# (list) Garden requirements
#garden_requirements =

# (str) Presplash of the application
#presplash.filename = %(source.dir)s/data/presplash.png

# (str) Icon of the application
#icon.filename = %(source.dir)s/data/icon.png

# (str) Supported orientation (one of landscape, portrait or all)
orientation = landscape

# (bool) Indicate if the application should be fullscreen or not
fullscreen = 1


#
# Android specific
#

# (list) Permissions
#android.permissions = INTERNET

# (int) Android API to use
#android.api = 14

# (int) Minimum API required (8 = Android 2.2 devices)
#android.minapi = 8

# (int) Android SDK version to use
#android.sdk = 21

# (str) Android NDK version to use
#android.ndk = 9c

# (bool) Use --private data storage (True) or --dir public storage     (False)
#android.private_storage = True

# (str) Android NDK directory (if empty, it will be automatically     downloaded.)
#android.ndk_path =

# (str) Android SDK directory (if empty, it will be automatically downloaded.)
#android.sdk_path =

# (str) python-for-android git clone directory (if empty, it will be automatically cloned from github)
#android.p4a_dir =

# (list) python-for-android whitelist
#android.p4a_whitelist =

# (str) Android entry point, default is ok for Kivy-based app
#android.entrypoint = org.renpy.android.PythonActivity

# (list) List of Java .jar files to add to the libs so that pyjnius         can access
# their classes. Don't add jars that you do not need, since extra jars     can slow
# down the build process. Allows wildcards matching, for example:
# OUYA-ODK/libs/*.jar
#android.add_jars = foo.jar,bar.jar,path/to/more/*.jar

# (list) List of Java files to add to the android project (can be java         or a
# directory containing the files)
#android.add_src =

# (str) python-for-android branch to use, if not master, useful to try
# not yet merged features.
#android.branch = master

# (str) OUYA Console category. Should be one of GAME or APP
# If you leave this blank, OUYA support will not be enabled
#android.ouya.category = GAME

# (str) Filename of OUYA Console icon. It must be a 732x412 png image.
#android.ouya.icon.filename = %(source.dir)s/data/ouya_icon.png

# (str) XML file to include as an intent filters in <activity> tag
#android.manifest.intent_filters =

# (list) Android additionnal libraries to copy into libs/armeabi
#android.add_libs_armeabi = libs/android/*.so
#android.add_libs_armeabi_v7a = libs/android-v7/*.so
#android.add_libs_x86 = libs/android-x86/*.so
#android.add_libs_mips = libs/android-mips/*.so

# (bool) Indicate whether the screen should stay on
# Don't forget to add the WAKE_LOCK permission if you set this to True
#android.wakelock = False

# (list) Android application meta-data to set (key=value format)
#android.meta_data =

# (list) Android library project to add (will be added in the
# project.properties automatically.)
#android.library_references =

#
# iOS specific
#

# (str) Name of the certificate to use for signing the debug version
# Get a list of available identities: buildozer ios list_identities
#ios.codesign.debug = "iPhone Developer: <lastname> <firstname>         (<hexstring>)"

# (str) Name of the certificate to use for signing the release version
#ios.codesign.release = %(ios.codesign.debug)s


[buildozer]

# (int) Log level (0 = error only, 1 = info, 2 = debug (with command         output))
log_level = 2

# (int) Display warning if buildozer is run as root (0 = False, 1 =         True)
warn_on_root = 1


#    -----------------------------------------------------------------    ------------
#    List as sections
#
#    You can define all the "list" as [section:key].
#    Each line will be considered as a option to the list.
#    Let's take [app] / source.exclude_patterns.
#    Instead of doing:
#
#[app]
#source.exclude_patterns =     license,data/audio/*.wav,data/images/original/*
#
#    This can be translated into:
#
#[app:source.exclude_patterns]
#license
#data/audio/*.wav
#data/images/original/*
#


#    ---------------------------------------------------------------------    --------
#    Profiles
#
#    You can extend section / key with a profile
#    For example, you want to deploy a demo version of your     application     without
#    HD content. You could first change the title to add "(demo)" in the     name
#    and extend the excluded directories to remove the HD content.
#
#[app@demo]
#title = My Application (demo)
#
#[app:source.exclude_patterns@demo]
#images/hd/*
#
#    Then, invoke the command line with the "demo" profile:

#buildozer --profile demo android debug