message: Sometimes the string data field contains a protobuf, so ignore failures to decode
  Summary: for compile_begin events, there is an HLO graph protobuf in the field
  Test Plan: unit tests ok on python2
  Reviewers: georgep
diff: @@ -52,7 +52,10 @@ def extract_all_strings_from_event_trace(events):
  result = ""
  for e in events:
  evt = IpuTraceEvent.FromString(e)
  + try:
  result = result + evt.data_str.decode('utf-8')
  + except UnicodeDecodeError:
  + pass
  return result
  def extract_all_types_from_event_trace(events):
  @@ -75,7 +78,10 @@ def extract_all_io_events(events):
  evt = IpuTraceEvent.FromString(e)
  if evt.type in [IpuTraceEvent.HOST_TO_DEVICE_TRANSFER,
  IpuTraceEvent.DEVICE_TO_HOST_TRANSFER]:
  + try:
  result += [(evt.type, evt.data_str.decode('utf-8'))]
  + except UnicodeDecodeError:
  + pass
  return result
  def ipu_compile_summary(name, op_list, collections=None):
  