With the addition of the GCP Pubsub Publish Operator, the preprocessor for this converts message data property to bytes. However, bytes are not supported when generating the actual Python DAGs. The below is the error seen:

...
  File "/home/jenkins/workspace/bigdataconf-test-pr/venv/lib/python3.7/site-packages/boundary_layer/builders/util.py", line 132, in format_value
    type(value)))
Exception: Cannot format value `b'U1VDQ0VTUw=='`: no handler for type <class 'bytes'>

The solution for this likely lies in boundary_layer/builders/util.py in the function format_value. However, I know that byte literals are treated differently in Python 2 and Python 3, so this might be a little more involved of a change. Regardless, there may be future instances when generating a DAG with byte literals is required as well, so it might be worth looking into.