error with DirectRunner

[Allie Chen]

Hi,

I have a project that started failing with DirectRunner, but works well
using DataflowRunner (last working version is 2.4). The error message I
received are:
line 1088, in run_stage
  pipeline_components.pcollections[actual_pcoll_id].coder_id]]
KeyError: u'ref_Coder_WindowedValueCoder_1'

I have simplified the pipeline to the following example. Can someone please
take a look? Many thanks!

Allie


import apache_beam as beam
import argparse
from apache_beam import transforms
from apache_beam import pvalue
from apache_beam.options import pipeline_options


def _copy_number(number, side=None):
  yield number


def fn_sum(values):
  return sum(values)


def run(argv=None):
  parser = argparse.ArgumentParser()
  _, pipeline_args = parser.parse_known_args(argv)
  options = pipeline_options.PipelineOptions(pipeline_args)
  numbers = [1, 2]
  with beam.Pipeline(options=options) as p:
    sum_1 = (p
             | 'ReadNumber1' >> transforms.Create(numbers)
             | 'CalculateSum1' >> beam.CombineGlobally(fn_sum))

    sum_2 = (p
             | 'ReadNumber2' >> transforms.Create(numbers)
             | beam.ParDo(_copy_number, pvalue.AsSingleton(sum_1))
             | 'CalculateSum2' >> beam.CombineGlobally(fn_sum))

    _ = ((sum_1, sum_2)
         | beam.Flatten()
         | 'CalculateSum3' >> beam.CombineGlobally(fn_sum)
         | beam.io.WriteToText('gs://BUCKET/sum'))