{"record":{"id":"785b2071474ad1f2","repo":"vllm-project/vllm","slug":"invalid-backend-for-piecewise-compilation-self-b","errorCode":null,"errorMessage":"Invalid backend for piecewise compilation: {self.backend}","messagePattern":"Invalid backend for piecewise compilation: (.+?)","errorType":"validation","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"vllm/config/compilation.py","lineNumber":1029,"sourceCode":"\n        enabled_ops = {op[1:] for op in self.custom_ops if op.startswith(\"+\")}\n        disabled_ops = {op[1:] for op in self.custom_ops if op.startswith(\"-\")}\n        conflicting_ops = sorted(enabled_ops & disabled_ops)\n        if conflicting_ops:\n            raise ValueError(\n                \"custom_ops cannot both enable and disable the same operation(s): \"\n                f\"{', '.join(conflicting_ops)}. Remove either the '+' or '-' directive\"\n            )\n\n        # Currently only eager and inductor backend are supported.\n        # for piecewise compilation. Custom backends are not supported for\n        # piecewise compilation. Update when more backends are supported.\n        if self.mode == CompilationMode.VLLM_COMPILE and self.backend not in [\n            \"\",\n            \"eager\",\n            \"inductor\",\n        ]:\n            raise ValueError(\n                f\"Invalid backend for piecewise compilation: {self.backend}\"\n            )\n\n        # Validate encoder CUDA graph configuration\n        if (\n            self.cudagraph_mm_encoder\n            and self.encoder_cudagraph_max_vision_items_per_batch < 0\n        ):\n            raise ValueError(\n                \"encoder_cudagraph_max_vision_items_per_batch must be \"\n                \"non-negative (0 = auto-infer)\"\n            )\n        if (\n            self.cudagraph_mm_encoder\n            and self.encoder_cudagraph_max_frames_per_batch is not None\n            and self.encoder_cudagraph_max_frames_per_batch < 0\n        ):\n            raise ValueError(","sourceCodeStart":1011,"sourceCodeEnd":1047,"githubUrl":"https://github.com/vllm-project/vllm/blob/c794754062d49a8fdb63ab3c5215b488b865030c/vllm/config/compilation.py#L1011-L1047","documentation":"Error \"Invalid backend for piecewise compilation: {self.backend}\" thrown in vllm-project/vllm.","triggerScenarios":"Raised at vllm/config/compilation.py:1029 when validation fails: Invalid backend for piecewise compilation. 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/compilation.py:1029 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 a supported piecewise compilation backend (e.g. 'inductor') instead of the current one.","Check CompilationConfig documentation for valid split/piecewise backends."],"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"}