message: Fixed typo in comment about docker build argument.
diff: @@ -23,6 +23,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
  ENV CI_BUILD_PYTHON python
  -# Check out TensorFlow source code if --build_arg CHECKOUT_TENSORFLOW=1
  +# Check out TensorFlow source code if --build-arg CHECKOUT_TF_SRC=1
  ARG CHECKOUT_TF_SRC=0
  RUN test "${CHECKOUT_TF_SRC}" -eq 1 && git clone https://github.com/tensorflow/tensorflow.git /tensorflow_src
  