Name of failing test

uv pip install --system torchao==0.13.0 && VLLM_TEST_FORCE_LOAD_FORMAT=auto pytest -v -s quantization/ --ignore quantization/test_blackwell_moe.py

Basic information

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

🧪 Describe the failing test

Multiple Failing Tests in quantization test suite (33 failures)

Common failure patterns across quantization tests:

Pattern 1 - Unsupported on ROCm:

• test_model_rtn_startup - ValidationError: "rtn quantization is currently not supported in rocm"
• Expected behavior: Test should be skipped on ROCm platform

Pattern 2 - Engine Core Initialization Failures:

• test_load_fp16_model (8 variants), test_ptpc_fp8_rocm (6 variants), test_pre_quantized_model, test_scaled_fp8_quant (2 variants)
• Failure: RuntimeError during wait_for_engine_startup → engine core subprocess exits prematurely
• Same root cause as compilation test failures: multiprocessing initialization issues in spawned workers

Pattern 3 - Model/Config Issues:

• test_auto_gptq (6 variants), test_cpu_offload_gptq, test_cpu_offload_compressed_tensors, test_gptq_with_dynamic (2 variants), test_custom_quant
• Likely cause: AssertionErrors suggest model loading or weight quantization configuration mismatches specific to ROCm

Pattern 4 - Specific Model Failures:

• test_experts_int8 for Jamba/Plamo models, test_compressed_tensors_nvfp4, test_compressed_tensors_fp8_block_enabled
• Likely cause: ROCm-specific kernel or quantization format incompatibilities

Root causes:

1. Missing platform checks - Tests not skipping unsupported quantization methods on ROCm
2. Same multiprocessing/CUDA initialization issue affecting engine startup across multiple quantization configs
3. ROCm-specific quantization kernel/format compatibility issues not properly handled
4. Model architecture inspection triggering device capability checks in forked processes (similar to data_parallel.py issue)

📝 History of failing test

AMD-CI build Buildkite references:

• 1041
• 1077
• 1088
• 1109
• 1111

CC List.

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