title: Error loading tensorflow_datasets: error with Google cloud
body: <p>When loading tensorflow_dataset, I got following error:</p>
  <pre><code>ds = tfds.load('mnist', split='train', shuffle_files=True)
  ---------------------------------------------------------------------------
  FailedPreconditionError                   Traceback (most recent call last)
  ~/anaconda3/lib/python3.7/site-packages/tensorflow_datasets/core/utils/py_utils.py in try_reraise(*args, **kwargs)
      398   try:
  --&gt; 399     yield
      400   except Exception:   # pylint: disable=broad-except
  
  ~/anaconda3/lib/python3.7/site-packages/tensorflow_datasets/core/registered.py in builder(name, **builder_init_kwargs)
      243       prefix=&quot;Failed to construct dataset {}&quot;.format(name)):
  --&gt; 244     return builder_cls(name)(**builder_kwargs)
      245 
  
  ~/anaconda3/lib/python3.7/site-packages/tensorflow_datasets/core/api_utils.py in disallow_positional_args_dec(fn, instance, args, kwargs)
       68     _check_required(fn, kwargs)
  ---&gt; 69     return fn(*args, **kwargs)
       70 
  
  ~/anaconda3/lib/python3.7/site-packages/tensorflow_datasets/core/dataset_builder.py in __init__(self, data_dir, config, version)
      205     else:  # Use the code version (do not restore data)
  --&gt; 206       self.info.initialize_from_bucket()
      207 
  
  ~/anaconda3/lib/python3.7/site-packages/tensorflow_datasets/core/dataset_info.py in initialize_from_bucket(self)
      422     tmp_dir = tempfile.mkdtemp(&quot;tfds&quot;)
  --&gt; 423     data_files = gcs_utils.gcs_dataset_info_files(self.full_name)
      424     if not data_files:
  
  ~/anaconda3/lib/python3.7/site-packages/tensorflow_datasets/core/utils/gcs_utils.py in gcs_dataset_info_files(dataset_dir)
       70   &quot;&quot;&quot;Return paths to GCS files in the given dataset directory.&quot;&quot;&quot;
  ---&gt; 71   return gcs_listdir(posixpath.join(GCS_DATASET_INFO_DIR, dataset_dir))
       72 
  
  ~/anaconda3/lib/python3.7/site-packages/tensorflow_datasets/core/utils/gcs_utils.py in gcs_listdir(dir_name)
       63   root_dir = gcs_path(dir_name)
  ---&gt; 64   if is_gcs_disabled() or not tf.io.gfile.exists(root_dir):
       65     return None
  
  ~/anaconda3/lib/python3.7/site-packages/tensorflow/python/lib/io/file_io.py in file_exists_v2(path)
      266   try:
  --&gt; 267     _pywrap_file_io.FileExists(compat.as_bytes(path))
      268   except errors.NotFoundError:
  
  FailedPreconditionError: Error executing an HTTP request: libcurl code 77 meaning 'Problem with the SSL CA cert (path? access rights?)', error details: error setting certificate verify locations:
    CAfile: /etc/ssl/certs/ca-certificates.crt
    CApath: none
       when reading metadata of gs://tfds-data/dataset_info/mnist/3.0.1
  </code></pre>
  <p>In addition, the following appeared on cmd line:</p>
  <p>2020-08-23 12:12:46.444195: W tensorflow/core/platform/cloud/google_auth_provider.cc:184] All attempts to get a Google authentication bearer token failed, returning an empty token. Retrieving token from files failed with &quot;Not found: Could not locate the credentials file.&quot;. Retrieving token from GCE failed with &quot;Failed precondition: Error executing an HTTP request: libcurl code 6 meaning 'Couldn't resolve host name', error details: Couldn't resolve host 'metadata'&quot;.</p>
  <p>I am behind a corporate firewall, anything I can do to resolve this issue which looks like Google cloud authentication/certificate issue.</p>
  <p>Thanks.</p>