sbpack fails to upload workflow pre-packed with cwltool

[golharam]

We have a case where we pack a workflow using 'cwltool --pack', then would like to upload that pre-packed workflow to SBG. When doing so, we encounter:

Traceback (most recent call last):
  File "env/bin/sbpack", line 8, in <module>
    sys.exit(main())
  File "/scratch/PDX/env/lib64/python3.7/site-packages/sbpack/pack.py", line 419, in main
    api.apps.create_revision(id=appid, raw=cwl, revision=app.revision + 1)
  File "/scratch/PDX/env/lib64/python3.7/site-packages/sevenbridges/models/app.py", line 156, in create_revision
    id=id, revision=revision), data=raw).json()
  File "/scratch/PDX/env/lib64/python3.7/site-packages/sevenbridges/http/client.py", line 329, in post
    data=data, append_base=append_base)
  File "/scratch/PDX/env/lib64/python3.7/site-packages/sevenbridges/decorators.py", line 50, in wrapper
    return func(http_client, *args, **kwargs)
  File "/scratch/PDX/env/lib64/python3.7/site-packages/sevenbridges/decorators.py", line 95, in wrapper
    raise e
sevenbridges.errors.BadRequest: Bad Request.

It seems the packed workflow is not a dictionary object as the API is expecting.