The icebreaker uart.py example fails with an error

[JamesTimothyMeech]

james@james-Laptop-13th-Gen-Intel-Core:~/Desktop/icebreaker-amaranth-examples/icebreaker/uart$ python3 uart.py 
Traceback (most recent call last):
  File "/home/james/Desktop/icebreaker-amaranth-examples/icebreaker/uart/uart.py", line 358, in <module>
    plat.build(_LoopbackTest(), do_program=True)
  File "/home/james/.local/lib/python3.10/site-packages/amaranth/build/plat.py", line 105, in build
    plan = self.prepare(elaboratable, name, **kwargs)
  File "/home/james/.local/lib/python3.10/site-packages/amaranth/build/plat.py", line 145, in prepare
    fragment = Fragment.get(elaboratable, self)
  File "/home/james/.local/lib/python3.10/site-packages/amaranth/hdl/ir.py", line 42, in get
    new_obj = obj.elaborate(platform)
  File "/home/james/Desktop/icebreaker-amaranth-examples/icebreaker/uart/uart.py", line 296, in elaborate
    leds = Cat([platform.request("led_r"), platform.request("led_g")])
  File "/home/james/.local/lib/python3.10/site-packages/amaranth/hdl/ast.py", line 934, in __init__
    self.parts.append(Value.cast(arg))
  File "/home/james/.local/lib/python3.10/site-packages/amaranth/hdl/ast.py", line 178, in cast
    raise TypeError("Object {!r} cannot be converted to an Amaranth value".format(obj))
TypeError: Object flipped((rec led_r_0 o)) cannot be converted to an Amaranth value