Multiclock simulation broken about amaranth HOT 6 CLOSED

$ python3 simclk.py
step
  curr_dirty any
    wait_deadline {}, ts 0.0, delta 0.0
step
  processes > suspended
step
  processes > suspended
step
  run passive
step
  curr_dirty any
    wait_deadline {<generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd295c8>: 2.5, <generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd29620>: 3.0}, ts 1.5, delta 1e-10
     wait_deadline.values dict_values([2.5, 3.0])
step
  run passive
step
  curr_dirty any
    wait_deadline {<generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd29620>: 3.0, <generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd295c8>: 5.0}, ts 2.5, delta 1e-10
     wait_deadline.values dict_values([3.0, 5.0])
step
  run passive
step
  curr_dirty any
    wait_deadline {<generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd295c8>: 5.0, <generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd29620>: 4.5}, ts 3.0, delta 0.0
     wait_deadline.values dict_values([5.0, 4.5])
step
  run passive
step
  curr_dirty any
    wait_deadline {<generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd295c8>: 5.0, <generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd29620>: 6.0}, ts 4.5, delta 1e-10
     wait_deadline.values dict_values([5.0, 6.0])
step
  run passive
step
  curr_dirty any
    wait_deadline {<generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd29620>: 6.0, <generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd295c8>: 7.5}, ts 5.0, delta 0.0
     wait_deadline.values dict_values([6.0, 7.5])
step
  run passive
step
  curr_dirty any
    wait_deadline {<generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd295c8>: 7.5, <generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd29620>: 7.5}, ts 6.0, delta 0.0
     wait_deadline.values dict_values([7.5, 7.5])
step
  run passive
step
  curr_dirty any
    wait_deadline {<generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd29620>: 7.5, <generator object Simulator.add_clock.<locals>.clk_process at 0x7f447bd295c8>: 10.0}, ts 7.5, delta 1e-10
     wait_deadline.values dict_values([7.5, 10.0])
Traceback (most recent call last):
  File "simclk.py", line 11, in <module>
    sim.run_until(100, run_passive=True)
  File "/home/robertbaruch/.local/lib/python3.6/site-packages/nmigen/back/pysim.py", line 854, in run_until
    if not self.step(run_passive):
  File "/home/robertbaruch/.local/lib/python3.6/site-packages/nmigen/back/pysim.py", line 810, in step
    raise DeadlineError("Delta cycles exceeded process deadline; combinatorial loop?")
nmigen.back.pysim.DeadlineError: Delta cycles exceeded process deadline; combinatorial loop?