Sporadic error when used with packaged grow app

[jeremydw]

When using the packaged grow app (rather than running grow from source), we sometimes run into this error when uploading a file to GCS.

BuildError: Error building <grow.rendering.render_controller.RenderDocumentController object at 0x11b447e50>: media_filename must be str or MediaUpload.

The problem is non-existent when using grow from source.

Traceback:

  File "extensions/google_drive_to_gcs/google_drive_to_gcs.py", line 142, in do_drive_to_gcs
    return syncer.execute(file_id, bucket_path)
  File "extensions/google_drive_to_gcs/google_drive_to_gcs.py", line 121, in execute
    self.storage_service, gs_path, fh, mimetype)
  File "extensions/google_drive_to_gcs/google_drive_to_gcs.py", line 60, in upload_google_storage_file
    media_body=media, name=path, bucket=bucket)
  File "site-packages/googleapiclient/discovery.py", line 709, in method
TypeError: media_filename must be str or MediaUpload.