1 files changed, 6 insertions, 3 deletions
diff --git a/tensorflow/contrib/cluster_resolver/python/training/tpu_cluster_resolver.py b/tensorflow/contrib/cluster_resolver/python/training/tpu_cluster_resolver.py
index 8f521ffee4..1ab150d74a 100644
--- a/tensorflow/contrib/cluster_resolver/python/training/tpu_cluster_resolver.py
+++ b/tensorflow/contrib/cluster_resolver/python/training/tpu_cluster_resolver.py
@@ -148,6 +148,9 @@ class TPUClusterResolver(ClusterResolver):
       else:
         tpu = self._envVarFallback()
 
+    if tpu is None:
+      raise ValueError('Please provide a TPU Name to connect to.')
+
     self._tpu = compat.as_bytes(tpu)  # self._tpu is always bytes
     self._job_name = job_name
     self._credentials = credentials
@@ -259,11 +262,11 @@ class TPUClusterResolver(ClusterResolver):
 
       if 'state' in response and response['state'] != 'READY':
         raise RuntimeError('TPU "%s" is not yet ready; state: "%s"' %
-                           (self._tpu, response['state']))
+                           (compat.as_text(self._tpu), response['state']))
 
       if 'health' in response and response['health'] != 'HEALTHY':
-        raise RuntimeError('TPU "%s" is unhealthy: "%s"' % (self._tpu,
-                                                            response['health']))
+        raise RuntimeError('TPU "%s" is unhealthy: "%s"' %
+                           (compat.as_text(self._tpu), response['health']))
 
       if 'networkEndpoints' in response:
         worker_list = [