[Android] Catch device exceptions from individual test shards.

build/android/pylib/base/test_dispatcher.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Dispatches tests, either sharding or replicating them.
 
 Performs the following steps:
 * Create a test collection factory, using the given tests
   - If sharding: test collection factory returns the same shared test collection
     to all test runners
@@ skipping 170 matching lines @@
   threads = [
       reraiser_thread.ReraiserThread(
           _RunTestsFromQueue,
           [r, tc, results, watcher, num_retries, tag_results_with_device],
           name=r.device_serial[-4:])
       for r, tc in zip(runners, test_collections)]
 
   workers = reraiser_thread.ReraiserThreadGroup(threads)
   workers.StartAll()
 
-  # Catch DeviceUnreachableErrors and set a warning exit code
   try:
     workers.JoinAll(watcher)
-  except device_errors.DeviceUnreachableError as e:
-    logging.error(e)
+  except device_errors.CommandFailedError:
+    logging.exception('Command failed on device.')
+  except device_errors.CommandFailedError:
+    logging.exception('Command timed out on device.')
+  except device_errors.DeviceUnreachableError:
+    logging.exception('Device became unreachable.')
 
   if not all((len(tc) == 0 for tc in test_collections)):
     logging.error('Only ran %d tests (all devices are likely offline).' %
                   len(results))
     for tc in test_collections:
       run_results.AddResults(base_test_result.BaseTestResult(
           t, base_test_result.ResultType.UNKNOWN) for t in tc.test_names())
 
   for r in results:
     run_results.AddTestRunResults(r)
@@ skipping 117 matching lines @@
   try:
     return _RunAllTests(runners, test_collection_factory,
                         num_retries, test_timeout, tag_results_with_device)
   finally:
     try:
       _TearDownRunners(runners, setup_timeout)
     except device_errors.DeviceUnreachableError as e:
       logging.warning('Device unresponsive during TearDown: [%s]', e)
     except Exception as e:
       logging.error('Unexpected exception caught during TearDown: %s' % str(e))