[ROCm][CI] Fix engine teardown and text normalization to stabilize voxtral test (#37138)

Signed-off-by: Andreas Karatzas <akaratza@amd.com>

tests/models/multimodal/generation/test_voxtral_realtime.py

 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import contextlib
 from dataclasses import asdict
 
 import pytest
+import pytest_asyncio
 from mistral_common.audio import Audio
 from mistral_common.protocol.instruct.chunk import RawAudio
 from mistral_common.protocol.transcription.request import (
@@ -17,18 +19,21 @@ from vllm.assets.audio import AudioAsset
 from vllm.engine.arg_utils import AsyncEngineArgs
 from vllm.v1.engine.async_llm import AsyncLLM
 
+from ....utils import ROCM_ENGINE_KWARGS
+
 MODEL_NAME = "mistralai/Voxtral-Mini-4B-Realtime-2602"
-ENGINE_CONFIG = dict(
-    model=MODEL_NAME,
-    max_model_len=8192,
-    max_num_seqs=4,
-    limit_mm_per_prompt={"audio": 1},
-    config_format="mistral",
-    load_format="mistral",
-    tokenizer_mode="mistral",
-    enforce_eager=True,
-    gpu_memory_utilization=0.9,
-)
+ENGINE_CONFIG = {
+    "model": MODEL_NAME,
+    "max_model_len": 8192,
+    "max_num_seqs": 4,
+    "limit_mm_per_prompt": {"audio": 1},
+    "config_format": "mistral",
+    "load_format": "mistral",
+    "tokenizer_mode": "mistral",
+    "enforce_eager": True,
+    "gpu_memory_utilization": 0.9,
+    **ROCM_ENGINE_KWARGS,
+}
 
 
 EXPECTED_TEXT = [
@@ -49,6 +54,14 @@ EXPECTED_TEXT = [
 ]
 
 
+def _normalize(texts: list[str]) -> list[str]:
+    # The model occasionally transcribes "OBS" as "a base hit" and
+    # "oh, my" as "oh my", but both are acoustically valid. Normalise so
+    # the assertion is stable across runs and hardware.
+    texts[1] = texts[1].replace("a base hit", "OBS").replace("oh my", "oh, my")
+    return texts
+
+
 @pytest.fixture
 def audio_assets() -> list[AudioAsset]:
     return [AudioAsset("mary_had_lamb"), AudioAsset("winning_call")]
@@ -60,15 +73,27 @@ def tokenizer() -> MistralTokenizer:
 
 
 @pytest.fixture
-def engine() -> LLM:
+def engine():
     engine_args = EngineArgs(**ENGINE_CONFIG)
-    return LLM(**asdict(engine_args))
+    llm = LLM(**asdict(engine_args))
+    try:
+        yield llm
+    finally:
+        with contextlib.suppress(Exception):
+            llm.llm_engine.engine_core.shutdown()
+        import torch
 
+        torch.accelerator.empty_cache()
 
-@pytest.fixture
-def async_engine() -> AsyncLLM:
+
+@pytest_asyncio.fixture
+async def async_engine():
     engine_args = AsyncEngineArgs(**ENGINE_CONFIG)
-    return AsyncLLM.from_engine_args(engine_args)
+    llm = AsyncLLM.from_engine_args(engine_args)
+    try:
+        yield llm
+    finally:
+        llm.shutdown()
 
 
 def test_voxtral_realtime_forward(audio_assets, tokenizer, engine):
@@ -108,8 +133,13 @@ def test_voxtral_realtime_forward(audio_assets, tokenizer, engine):
         sampling_params=sampling_params,
     )
 
-    texts = [out.outputs[0].text for out in outputs]
-    assert texts == EXPECTED_TEXT
+    texts = _normalize([out.outputs[0].text for out in outputs])
+    for i, (got, expected) in enumerate(zip(texts, EXPECTED_TEXT)):
+        assert got == expected, (
+            f"Output mismatch at index {i}:\n"
+            f"  got:      {got!r}\n"
+            f"  expected: {expected!r}"
+        )
 
 
 @pytest.mark.asyncio
@@ -149,9 +179,17 @@ async def test_voxtral_realtime_generator(audio_assets, tokenizer, async_engine)
 
         output_tokens_list.append(output_tokens)
 
-    texts = [
-        tokenizer.decode(output_tokens, special_token_policy=SpecialTokenPolicy.IGNORE)
+    texts = _normalize(
+        [
+            tokenizer.decode(
+                output_tokens, special_token_policy=SpecialTokenPolicy.IGNORE
+            )
             for output_tokens in output_tokens_list
         ]
-    texts[1] = texts[1].replace("a base hit", "OBS").replace("oh my", "oh, my")
-    assert texts == EXPECTED_TEXT
+    )
+    for i, (got, expected) in enumerate(zip(texts, EXPECTED_TEXT)):
+        assert got == expected, (
+            f"Output mismatch at index {i}:\n"
+            f"  got:      {got!r}\n"
+            f"  expected: {expected!r}"
+        )

tests/utils.py

@@ -122,6 +122,12 @@ ROCM_EXTRA_ARGS = (
     if current_platform.is_rocm()
     else []
 )
+# Python-API equivalent of ROCM_EXTRA_ARGS for use with EngineArgs kwargs.
+ROCM_ENGINE_KWARGS: dict = (
+    {"enable_prefix_caching": False, "max_num_seqs": 1}
+    if current_platform.is_rocm()
+    else {}
+)
 
 
 class RemoteVLLMServer: