error

Traceback (most recent call last):
  File "/home/emifre/Git/alink-hdl/spi_slave.py", line 76, in <module>
    sim = Simulator(m)
  File "/usr/lib/python3.8/site-packages/nmigen/back/pysim.py", line 916, in __init__
    self._fragment = Fragment.get(fragment, platform=None).prepare()
  File "/usr/lib/python3.8/site-packages/nmigen/hdl/ir.py", line 530, in prepare
    new_domains = fragment._propagate_domains(missing_domain)
  File "/usr/lib/python3.8/site-packages/nmigen/hdl/ir.py", line 378, in _propagate_domains
    self._propagate_domains_down()
  File "/usr/lib/python3.8/site-packages/nmigen/hdl/ir.py", line 340, in _propagate_domains_down
    assert self.domains[domain] is subfrag.domains[domain]
AssertionError