For example this job:
https://pinpoint-dot-chromeperf.appspot.com/job/11e42ae3e40000

Has a failed run where pinpoint reports:
Traceback (most recent call last):
  File "/base/data/home/apps/s~chromeperf/pinpoint:dev-dtu-2683d79b.413990457675791731/dashboard/pinpoint/models/quest/execution.py", line 95, in Poll
    self._Poll()
  File "/base/data/home/apps/s~chromeperf/pinpoint:dev-dtu-2683d79b.413990457675791731/dashboard/pinpoint/models/quest/run_test.py", line 240, in _Poll
    raise SwarmingTestError('The test failed. No Python '
SwarmingTestError: The test failed. No Python exception was found in the log.

However looking into the swarming task, the output does have:
Traceback (most recent call last):
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\story_runner.py", line 124, in _RunStoryAndProcessErrorIfNeeded
    state.WillRunStory(story)
  File "c:\b\s\w\ir\third_party\catapult\common\py_trace_event\py_trace_event\trace_event_impl\decorators.py", line 75, in traced_function
    return func(*args, **kwargs)
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\page\shared_page_state.py", line 245, in WillRunStory
    self.browser.tabs[0].WaitForDocumentReadyStateToBeComplete()
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\browser\tab_list.py", line 18, in __getitem__
    return self._tab_list_backend.__getitem__(index)
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\backends\chrome_inspector\inspector_backend_list.py", line 64, in __getitem__
    return self.GetBackendFromContextId(context_id)
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\backends\chrome_inspector\inspector_backend_list.py", line 75, in GetBackendFromContextId
    context_id)
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\backends\chrome_inspector\devtools_client_backend.py", line 594, in GetInspectorBackend
    self._app_backend.app, self._devtools_client, context)
  File "c:\b\s\w\ir\third_party\catapult\common\py_trace_event\py_trace_event\trace_event_impl\decorators.py", line 75, in traced_function
    return func(*args, **kwargs)
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\backends\chrome_inspector\inspector_backend.py", line 82, in __init__
    self._ConvertExceptionFromInspectorWebsocket(e)
  File "c:\b\s\w\ir\third_party\catapult\common\py_trace_event\py_trace_event\trace_event_impl\decorators.py", line 75, in traced_function
    return func(*args, **kwargs)
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\backends\chrome_inspector\inspector_backend.py", line 72, in __init__
    self._log = inspector_log.InspectorLog(self._websocket)
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\backends\chrome_inspector\inspector_log.py", line 19, in __init__
    self._Enable()
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\backends\chrome_inspector\inspector_log.py", line 29, in _Enable
    self._inspector_websocket.SyncRequest({'method': 'Log.enable'}, timeout)
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\backends\chrome_inspector\inspector_websocket.py", line 132, in SyncRequest
    res = self._Receive(timeout)
  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\backends\chrome_inspector\inspector_websocket.py", line 181, in _Receive
    raise WebSocketException(err)
TimeoutException
https://chrome-swarming.appspot.com/task?id=4131c555cd816710&refresh=10&show_raw=1&wide_logs=true