[Bug Report] broken tests for connect_four in CI

[David-GERARD]

Describe the bug

The following tests are failing in CI for any PR:

• Tutorial tests / tutorial-test (3.8, SB3/connect_four)
• Tutorial tests / tutorial-test (3.9, SB3/connect_four)
• Tutorial tests / tutorial-test (3.10, SB3/connect_four)
• Tutorial tests / tutorial-test (3.11, SB3/connect_four)

Code example

Error message:

Installed /opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/AutoROM/roms/zaxxon.bin
Done!
Starting training on connect_four_v3.
Traceback (most recent call last):
  File "/Users/davidgerard/Desktop/Farama/PettingZoo/tutorials/SB3/connect_four/sb3_connect_four_action_mask.py", line 188, in <module>
    train_action_mask(env_fn, steps=20_480, seed=0, **env_kwargs)
  File "/Users/davidgerard/Desktop/Farama/PettingZoo/tutorials/SB3/connect_four/sb3_connect_four_action_mask.py", line 86, in train_action_mask
    env = ActionMasker(env, mask_fn)  # Wrap to enable masking (SB3 function)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/site-packages/sb3_contrib/common/wrappers/action_masker.py", line 20, in __init__
    super().__init__(env)
  File "/Library/Frameworks/Python.framework/Versions/3.12/lib/python3.12/site-packages/gymnasium/core.py", line 278, in __init__
    assert isinstance(env, Env)
           ^^^^^^^^^^^^^^^^^^^^
AssertionError

Additional context:

• The env being examined has the following wrapper structure: <SB3ActionMaskWrapper<connect_four_v3>>.
• connect_four_v3 is inherited from pettingzoo.AECEnv.
• SB3ActionMaskWrapper is inherited from pettingzoo.utils.BaseWrapper itself inherited from pettingzoo.AECEnv.

[David-GERARD]

Update:

• The bug has been identified as having appeared with gymnasium v1.0.0a1, with no error encountered when using gymnasium v0.29.1.
• As pointed out by @pseudo-rnd-thoughts, the following warning indicates that the error likely comes from the deprecation of the method Wrapper.__get_attr__ in favour of the new Wrapper.get_wrapper_attr as per Add deprecation warnings for features removed in Gymnasium v1.0 Gymnasium#535
• It is still unclear to me why this change created the bug, but I am looking into it.

Partial log message in last successful run of the CI:

Installed /opt/hostedtoolcache/Python/3.10.15/x64/lib/python3.10/site-packages/AutoROM/roms/zaxxon.bin
Done!
/opt/hostedtoolcache/Python/3.10.15/x64/lib/python3.10/site-packages/gymnasium/core.py:311: UserWarning: 
WARN: env.action_masks to get variables from other wrappers is deprecated and will be removed in v1.0, to get this variable you can do `env.unwrapped.action_masks` for environment variables or `env.get_wrapper_attr('action_masks')` that will search the reminding wrappers.
  logger.warn(
Starting training on connect_four_v3.
Using cpu device
...