[CI Failure]: test_reward.py::test_prm_models - AttributeError: 'DynamicCache' object has no attribute 'get_usable_length'. Did you mean: 'get_seq_length'?

[russellb]

Name of failing test

models/language/pooling/test_reward.py::test_prm_models[True-half-Qwen/Qwen2.5-Math-PRM-7B]

Basic information

• Flaky test
• Can reproduce locally
• Caused by external libraries (e.g. bug in transformers)

🧪 Describe the failing test

[2025-08-06T21:39:31Z] FAILED models/language/pooling/test_reward.py::test_prm_models[True-half-Qwen/Qwen2.5-Math-PRM-7B] - AttributeError: 'DynamicCache' object has no attribute 'get_usable_length'. Did you mean: 'get_seq_length'?
[2025-08-06T21:39:31Z] FAILED models/language/pooling/test_reward.py::test_prm_models[False-half-Qwen/Qwen2.5-Math-PRM-7B] - AttributeError: 'DynamicCache' object has no attribute 'get_usable_length'. Did you mean: 'get_seq_length'?

📝 History of failing test

https://buildkite.com/organizations/vllm/analytics/suites/ci-1/tests/600d233a-e9e7-8f9f-b750-17eede6e1172?branch=main&period=1day

broken by #22327

CC List.

No response

[noooop]

Qwen/Qwen2.5-Math-PRM-7B hf Implementation does not support v4.54.1

refer to #21931 (comment)