check error for docker inspect

tools/run_tests/python_utils/dockerjob.py

@@ -76,8 +76,9 @@ def wait_for_healthy(cid, shortname, timeout_seconds):
   while time.time() - started < timeout_seconds:
     try:
       output = subprocess.check_output(
-          ['docker', 'inspect', '--format="{{.State.Health.Status}}"', cid],
+          ['docker', 'inspect', '--format="{{.State.Health.Status}}"', cid])
-          stderr=_DEVNULL)
+          #stderr=_DEVNULL)
+      print(output)
       if output.strip('\n') == 'healthy':
         return
     except subprocess.CalledProcessError as e: