hpo_bring_your_own_keras_container.ipynb failed CI

Link to the notebook:
https://github.com/aws/amazon-sagemaker-examples/blob/master/hyperparameter_tuning/keras_bring_your_own/hpo_bring_your_own_keras_container.ipynb

Error:

---------------------------------------------------------------------------
Exception encountered at "In [3]":
---------------------------------------------------------------------------
CalledProcessError Traceback (most recent call last)
in
24
25 print('building image:'+image_name)
---> 26 build_image(image_name, tensorflow_version_tag)

in build_image(name, version)
7 def build_image(name, version):
8 cmd = 'docker build -t %s --build-arg VERSION=%s -f Dockerfile .' % (name, version)
----> 9 subprocess.check_call(shlex.split(cmd))
10
11 #version tag can be found at https://hub.docker.com/r/tensorflow/tensorflow/tags/

/usr/local/lib/python3.7/subpro

[...]

CalledProcessError: Command '['docker', 'build', '-t', '521695447989.dkr.ecr.us-west-2.amazonaws.com/test:tensorflow-1.10.1', '--build-arg', 'VERSION=1.10.1', '-f', 'Dockerfile', '.']' returned non-zero exit status 1.

Open hyperparameter_tuning/keras_bring_your_own/hpo_bring_your_own_keras_container.ipynb and inspect In [3], especially build_image and the Dockerfile command. Reproduce the reported docker build using TensorFlow version 1.10.1, then identify the build failure; done means the notebook passes CI.

Written by the indexing model from the issue text.