The error from the bot:

(ERROR) 2019-01-17 16:05:16,890 tracing_controller_backend.CollectAgentTraceData:316  Error when deleting c:\b\s\w\it9a8qn1\tmpzcednf, will try again at exit.

Traceback (most recent call last):

  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\platform\tracing_controller_backend.py", line 312, in CollectAgentTraceData

    os.remove(self._trace_log)

WindowsError: [Error 32] The process cannot access the file because it is being used by another process: 'c:\\b\\s\\w\\it9a8qn1\\tmpzcednf'

(INFO) 2019-01-17 16:05:16,944 trace_data.Serialize:192  Trace sizes in bytes: {'traceEvents': 140868371L, 'telemetry': 163916L}

(INFO) 2019-01-17 16:05:26,348 trace_data.Serialize:201  trace2html finished in 9.40 seconds.

(INFO) 2019-01-17 16:05:26,348 timeline_based_measurement._ComputeTimelineBasedMetrics:317  Starting to compute metrics on trace

(INFO) 2019-01-17 16:06:07,578 timeline_based_measurement._ComputeTimelineBasedMetrics:323  Processing resulting traces took 41.230 seconds

(ERROR) 2019-01-17 16:06:07,622 story_runner.ProcessError:116  Possibly handleable error. Will try to restart shared state

Traceback (most recent call last):

  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\story_runner.py", line 144, in _RunStoryAndProcessErrorIfNeeded

    test.Measure(state.platform, results)

  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\web_perf\timeline_based_measurement.py", line 281, in Measure

    self._ComputeTimelineBasedMetrics(results, trace_value)

  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\web_perf\timeline_based_measurement.py", line 330, in _ComputeTimelineBasedMetrics

    results.ImportHistogramDicts(histogram_dicts)

  File "c:\b\s\w\ir\third_party\catapult\telemetry\telemetry\internal\results\page_test_results.py", line 502, in ImportHistogramDicts

    histograms.ImportDicts(histogram_dicts)

  File "c:\b\s\w\ir\third_party\catapult\tracing\tracing\value\histogram_set.py", line 88, in ImportDicts

    hist = histogram_module.Histogram.FromDict(d)

  File "c:\b\s\w\ir\third_party\catapult\tracing\tracing\value\histogram.py", line 646, in FromDict

    hist._bins[i].FromDict(bin_dct)

  File "c:\b\s\w\ir\third_party\catapult\tracing\tracing\value\histogram.py", line 469, in FromDict

    diagnostic_map_dict))

  File "c:\b\s\w\ir\third_party\catapult\tracing\tracing\value\histogram.py", line 388, in FromDict

    dm.AddDicts(dct)

  File "c:\b\s\w\ir\third_party\catapult\tracing\tracing\value\histogram.py", line 392, in AddDicts

    for name, diagnostic_dict in dct.items():

AttributeError: 'NoneType' object has no attribute 'items'

(

Ben, looks like there is a bug in histogram.py. git blame suggests that you're familiar with this code. Who would be the right owner for this?

For some reason bin_dict in None in:

      for i, bin_dct in dct['allBins'].items():
          i = int(i)
          hist._bins[i] = HistogramBin(hist._bins[i].range)
          hist._bins[i].FromDict(bin_dct)

https://cs.chromium.org/chromium/src/third_party/catapult/tracing/tracing/value/histogram.py?rcl=8e77731b13637a124d29b756a3e264b9cfcc493d&l=646