Luigi throws TaskClassAmbigiousException even upon successful run

[zfisch]

our pipeline runs are succeeding but throwing TaskClassAmbigiousException at the very end

Scheduled 69 tasks of which:
* 69 ran successfully:
    - 1 AddBayesdelScores()
    - 1 AggregateMergedOutput()
    - 1 AppendCAID()
    - 1 AppendMupitStructure()
    - 1 AppendVRId()
    ...

This progress looks :) because there were no failed tasks or missing dependencies

===== Luigi Execution Summary =====

Traceback (most recent call last):
  File "/usr/local/lib/python3.8/runpy.py", line 193, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/local/lib/python3.8/runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "/usr/local/lib/python3.8/site-packages/luigi/__main__.py", line 20, in <module>
    luigi_run()
  File "/usr/local/lib/python3.8/site-packages/luigi/cmdline.py", line 9, in luigi_run
    run_with_retcodes(argv)
  File "/usr/local/lib/python3.8/site-packages/luigi/retcodes.py", line 85, in run_with_retcodes
    with luigi.cmdline_parser.CmdlineParser.global_instance(argv):
  File "/usr/local/lib/python3.8/contextlib.py", line 113, in __enter__
    return next(self.gen)
  File "/usr/local/lib/python3.8/site-packages/luigi/cmdline_parser.py", line 52, in global_instance
    new_value = CmdlineParser(cmdline_args)
  File "/usr/local/lib/python3.8/site-packages/luigi/cmdline_parser.py", line 76, in __init__
    Register.get_task_cls(root_task)
  File "/usr/local/lib/python3.8/site-packages/luigi/task_register.py", line 182, in get_task_cls
    raise TaskClassAmbigiousException('Task %r is ambiguous' % name)
luigi.task_register.TaskClassAmbigiousException: Task 'GenerateReleaseArchive' is ambiguous```