anchor.diff:  
   
   ENV ANDROID_NDK_HOME="${ANDROID_HOME}/android-ndk"
  -ENV ANDROID_NDK_VERSION="14b"
  +ENV ANDROID_NDK_VERSION="17c"
   ENV ANDROID_NDK_HOME_V="${ANDROID_NDK_HOME}-r${ANDROID_NDK_VERSION}"
   
   # get the latest version from https://developer.android.com/ndk/downloads/index.html
  
positive.code:     && cd python-for-android \
      && git remote add sombernight https://github.com/SomberNight/python-for-android \
      && git fetch --all \
      && git checkout 86eeec7c19679a5886d5e095ce0a43f1da138f87 \
      && python3 -m pip install -e .
  
  # build env vars
  
negative.code: RUN pip install --upgrade cython==0.29
  RUN python3 -m pip install --upgrade cython==0.29
  
  # prepare git
  RUN git config --global user.name "John Doe" \
      && git config --global user.email johndoe@example.com
  
  # install buildozer
  RUN cd /opt \
      && git clone https://github.com/kivy/buildozer \
  