[Bug]: Qwen 3.8 quark int4 loading failed.

[hnhyzz]

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The output of python collect_env.py

Your output of `python collect_env.py` here

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🐛 Describe the bug

When I was serving amd/Qwen3.8-27B-Quark-Qronos-INT4-W4A16 with the following command on AMD mi100 cards, I got error indicating that the dict was treated as a string.

vllm serve /models/Qwen-int4/ --dtype float16 --gpu-memory-utilization 0.96 --tensor-parallel-size 1 --pipeline-parallel-size 1 --data-parallel-size 1 --attention-backend TRITON_ATTN --mm-encoder-attn-backend TORCH_SDPA --max-model-len 32000 --max-num-seqs 4 --enable-prefix-caching --reasoning-parser qwen3 --enable-auto-tool-choice --tool-call-parser qwen3_coder --served-model-name 'Qwen' --api-key 'xxxx' --compilation-config '{"cudagraph_mode": "FULL_AND_PIECEWISE", "mode":3 }' --skip-mm-profiling --limit-mm-per-prompt '{"image": 0}' --max_num_batched_tokens 4096 --language-model-only "

(EngineCore pid=223) File "/workspace/vllm/model_executor/model_loader/base_loader.py", line 55, in load_model
(EngineCore pid=223) model = initialize_model(
(EngineCore pid=223) ^^^^^^^^^^^^^^^^^
(EngineCore pid=223) File "/workspace/vllm/tracing/otel.py", line 178, in sync_wrapper
(EngineCore pid=223) return func(*args, **kwargs)
(EngineCore pid=223) ^^^^^^^^^^^^^^^^^^^^^
(EngineCore pid=223) File "/workspace/vllm/model_executor/model_loader/utils.py", line 51, in initialize_model
(EngineCore pid=223) configure_quant_config(vllm_config.quant_config, model_class)
(EngineCore pid=223) File "/workspace/vllm/model_executor/model_loader/utils.py", line 279, in configure_quant_config
(EngineCore pid=223) quant_config.apply_vllm_mapper(hf_to_vllm_mapper.get_unstacked_mapper())
(EngineCore pid=223) File "/workspace/vllm/model_executor/layers/quantization/quark/quark.py", line 142, in apply_vllm_mapper
(EngineCore pid=223) quant_config_with_hf_to_vllm_mapper[k] = hf_to_vllm_mapper.apply_list(v)
(EngineCore pid=223) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
(EngineCore pid=223) File "/workspace/vllm/model_executor/models/utils.py", line 152, in apply_list
(EngineCore pid=223) if (out_name := self._map_name(name)) is not None
(EngineCore pid=223) ^^^^^^^^^^^^^^^^^^^^
(EngineCore pid=223) File "/workspace/vllm/model_executor/models/utils.py", line 77, in _map_name
(EngineCore pid=223) result = self._map_name_with_shard(key)
(EngineCore pid=223) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
(EngineCore pid=223) File "/workspace/vllm/model_executor/models/utils.py", line 88, in _map_name_with_shard
(EngineCore pid=223) if key.endswith(".kv_scale"):
(EngineCore pid=223) ^^^^^^^^^^^^
(EngineCore pid=223) AttributeError: 'dict' object has no attribute 'endswith'

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[github-actions]

CC @hongxiayang @tjtanaa @vllmellm @giuseppegrossi for ROCm-related issue

[github-actions]

Hi @hnhyzz, thanks for reporting this ROCm issue!

To help us investigate, please make sure the following information is included:

• A minimal reproducer (code snippet or script that triggers the issue)
• The full error message or traceback
• How you installed vLLM (Docker image name, pip install, or build from source steps)
• The command you used to launch vLLM (e.g., vllm serve ... or the Python script)
• Your GPU model and GFX architecture (e.g., MI300X / gfx942) — run rocminfo | grep gfx

Please provide any unchecked items above. This will help us reproduce and resolve the issue faster. Thank you!

[carter-smalls]

Looks like model loading fails with dict treated as string error on amd mi100.

Use badgr doctor to diagnostic classification of the error and guidance for fixing the gpu/runtime issue.

That should help confirm check rocm driver version compatibility.