{"record":{"id":"cfa23184d96a2a05","repo":"vllm-project/vllm","slug":"unknown-mamba-ssu-algorithm-self-ssu-algorithm","errorCode":null,"errorMessage":"Unknown Mamba SSU algorithm: '{self.ssu_algorithm}'. Valid options are: {valid}","messagePattern":"Unknown Mamba SSU algorithm: '(.+?)'\\. Valid options are: (.+?)","errorType":"validation","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"vllm/config/mamba.py","lineNumber":72,"sourceCode":"    None defaults to FlashInfer's \"auto\" algorithm. Forced algorithms must\n    be supported by FlashInfer for the active GPU, state dtype, and decoding\n    mode.\"\"\"\n\n    @field_validator(\"backend\", mode=\"before\")\n    @classmethod\n    def validate_backend_before(cls, value: Any) -> Any:\n        \"\"\"Enable parsing of the `backend` enum type from string.\"\"\"\n        if isinstance(value, str):\n            return MambaBackendEnum[value.upper()]\n        return value\n\n    def validate_ssu_algorithm(self) -> None:\n        if self.ssu_algorithm is None:\n            return\n        valid_algorithms = get_args(MambaSSUAlgorithm)\n        if self.ssu_algorithm not in valid_algorithms:\n            valid = \", \".join(valid_algorithms)\n            raise ValueError(\n                f\"Unknown Mamba SSU algorithm: '{self.ssu_algorithm}'. \"\n                f\"Valid options are: {valid}\"\n            )\n        if self.backend != MambaBackendEnum.FLASHINFER:\n            raise ValueError(\n                \"Mamba SSU algorithm selection is only supported with the \"\n                \"FlashInfer backend. Please set `--mamba-backend flashinfer`, \"\n                \"or omit `--mamba-ssu-algorithm`.\"\n            )\n\n    def __post_init__(self):\n        self.validate_ssu_algorithm()\n        if self.enable_stochastic_rounding:\n            from vllm.platforms import current_platform\n\n            if not current_platform.is_cuda():\n                raise ValueError(\n                    \"Stochastic rounding for Mamba cache is only supported \"","sourceCodeStart":54,"sourceCodeEnd":90,"githubUrl":"https://github.com/vllm-project/vllm/blob/c794754062d49a8fdb63ab3c5215b488b865030c/vllm/config/mamba.py#L54-L90","documentation":"Error \"Unknown Mamba SSU algorithm: '{self.ssu_algorithm}'. Valid options are: {valid}\" thrown in vllm-project/vllm.","triggerScenarios":"Raised at vllm/config/mamba.py:72 when validation fails: Unknown Mamba SSU algorithm. Typically triggered by an incompatible or incomplete vLLM configuration, an unsupported platform/backend combination, or a runtime resource/dependency that is missing.","commonSituations":"Commonly encountered at vllm/config/mamba.py:72 during vLLM startup/config validation or runtime setup when: (1) conflicting CLI flags or config fields are combined, (2) the current platform (CUDA/ROCm/CPU/XPU) or installed optional packages do not support the requested feature, or (3) a required value is absent or out of range. Resolve by correcting the configuration as described in the message, or by selecting a supported alternative.","solutions":["Choose one of the valid Mamba SSU algorithms listed in the error for --mamba-ssu-algorithm."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"c794754062d49a8fdb63ab3c5215b488b865030c","analyzedAt":"2026-08-14T21:17:39.825Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}