Muzero crashes when choosing spiel/backgammon

[artshar]

Search before asking

• I have searched the MuZero issues and found no similar bug report.

🐛 Describe the bug

Welcome to MuZero! Here's a list of games:
0. atari

1. breakout
2. cartpole
3. connect4
4. gomoku
5. gridworld
6. lunarlander
7. simple_grid
8. spiel
9. tictactoe
10. twentyone
    Enter a number to choose the game: 8
    2023-08-29 23:03:34,908 INFO worker.py:1621 -- Started a local Ray instance.
    Traceback (most recent call last):
    File "/home/server/muzero-general/muzero.py", line 650, in
    muzero = MuZero(game_name)
    ^^^^^^^^^^^^^^^^^
    File "/home/server/muzero-general/muzero.py", line 122, in init
    self.checkpoint["weights"], self.summary = copy.deepcopy(ray.get(cpu_weights))
    ^^^^^^^^^^^^^^^^^^^^
    File "/home/server/miniconda3/lib/python3.11/site-packages/ray/_private/auto_init_hook.py", line 24, in auto_init_wrapper
    return fn(*args, **kwargs)
    ^^^^^^^^^^^^^^^^^^^
    File "/home/server/miniconda3/lib/python3.11/site-packages/ray/_private/client_mode_hook.py", line 103, in wrapper
    return func(*args, **kwargs)
    ^^^^^^^^^^^^^^^^^^^^^
    File "/home/server/miniconda3/lib/python3.11/site-packages/ray/_private/worker.py", line 2524, in get
    raise value.as_instanceof_cause()
    ray.exceptions.RayTaskError(IndexError): ray::CPUActor.get_initial_weights() (pid=14044, ip=192.168.0.206, actor_id=cb6f54b46087791a64e1e24101000000, repr=<muzero.CPUActor object at 0x7fe752d29790>)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "/home/server/muzero-general/muzero.py", line 489, in get_initial_weights
    model = models.MuZeroNetwork(config)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "/home/server/muzero-general/models.py", line 23, in new
    return MuZeroResidualNetwork(
    ^^^^^^^^^^^^^^^^^^^^^^
    File "/home/server/muzero-general/models.py", line 463, in init
    else (reduced_channels_reward * observation_shape[1] * observation_shape[2])
    ~~~~~~~~~~~~~~~~~^^^
    IndexError: tuple index out of range

Add an example

Environment

Python 3.11.5(3.10.12)
Ubuntu 22.04
tourch 2.0.1+cu117

Minimal Reproducible Example

games/spiel.py line 23
game = pyspiel.load_game("backgammon")

python3.11 muzero.py
choose the game: 8

Additional

the error is reproduced on different hardware