{"record":{"id":"bd9ef9bbfd148333","repo":"apache/beam","slug":"unable-to-handle-s","errorCode":null,"errorMessage":"unable to handle %s","messagePattern":"unable to handle (.+?)","errorType":"validation","errorClass":"TypeInferenceError","httpStatus":null,"severity":"error","filePath":"sdks/python/apache_beam/typehints/trivial_inference.py","lineNumber":549,"sourceCode":"        if has_kwargs:\n          # TODO(BEAM-24755): Unimplemented. Requires same functionality as a\n          #   CALL_FUNCTION_KW implementation.\n          return_type = Any\n        else:\n          args = state.stack[-1]\n          _callable = state.stack[-2]\n          if isinstance(args, typehints.ListConstraint):\n            # Case where there's a single var_arg argument.\n            args = [args]\n          elif isinstance(args, typehints.TupleConstraint):\n            args = list(args._inner_types())\n          elif isinstance(args, typehints.SequenceTypeConstraint):\n            args = [element_type(args)] * len(\n                inspect.getfullargspec(_callable.value).args)\n          return_type = infer_return_type(\n              _callable.value, args, debug=debug, depth=depth - 1)\n      else:\n        raise TypeInferenceError('unable to handle %s' % opname)\n      state.stack[-pop_count:] = [return_type]\n    elif opname == 'CALL_METHOD':\n      pop_count = 1 + arg\n      # LOAD_METHOD will return a non-Const (Any) if loading from an Any.\n      if isinstance(state.stack[-pop_count], Const) and depth > 0:\n        return_type = infer_return_type(\n            state.stack[-pop_count].value,\n            state.stack[1 - pop_count:],\n            debug=debug,\n            depth=depth - 1)\n      else:\n        return_type = typehints.Any\n      state.stack[-pop_count:] = [return_type]\n    elif opname == 'CALL':\n      pop_count = 1 + arg\n      # Keyword Args case\n      if state.kw_names is not None:\n        if isinstance(state.stack[-pop_count], Const):","sourceCodeStart":531,"sourceCodeEnd":567,"githubUrl":"https://github.com/apache/beam/blob/12126d8942aaf848030c478b4c6a28c6af861c66/sdks/python/apache_beam/typehints/trivial_inference.py#L531-L567","documentation":"infer_return_type_func performs bytecode-level type inference over Python callables. When it hits a bytecode opname it does not implement in the call-handling branch, it raises TypeInferenceError('unable to handle %s'). It means Beam's inference engine cannot statically evaluate a bytecode instruction in the analyzed function.","triggerScenarios":"Running infer_return_type on a function whose bytecode contains an unsupported CALL/opcode variant (newer CPython opcodes, async constructs, or unusual call patterns) inside a callable passed to Beam with no explicit type hint.","commonSituations":"Using Beam type inference on code compiled by a newer Python version with opcodes the bundled inference doesn't know; using async generators, decorators, or star-args call shapes; running on an unsupported Python minor version.","solutions":["Add explicit type hints with with_output_types()/with_input_types() to bypass bytecode inference.","Downgrade/align to a Python version supported by your Beam release (check Beam's Python compatibility matrix).","Refactor the callable to use simpler, inference-friendly constructs.","Upgrade Beam to a version whose trivial_inference supports your interpreter's opcodes."],"exampleFix":"// before\np | beam.Map(my_func)  # my_func uses unsupported opcodes\n// after\np | beam.Map(my_func).with_output_types(int)","handlingStrategy":"fallback","validationCode":"import sys\nSUPPORTED = (3, 8) <= sys.version_info[:2] <= (3, 12)  # match Beam's support matrix\nassert SUPPORTED, 'Python version not supported by this Beam release'","typeGuard":"def inference_safe(fn) -> bool:\n    return not any(hasattr(fn, a) for a in ('__code__',)) or fn.__code__.co_flags & 0x80 == 0  # not a generator/coroutine","tryCatchPattern":"try:\n    t = infer_return_type(fn, args)\nexcept TypeInferenceError:\n    t = typehints.Any  # explicit hints were not provided","preventionTips":["Provide explicit type hints so bytecode inference is skipped","Check Beam's Python version compatibility matrix before upgrading interpreters","Keep transform callables simple and free of exotic constructs"],"tags":["python","apache-beam","type-inference","bytecode"],"backgroundTag":"unsupported-operation","analyzedSha":"12126d8942aaf848030c478b4c6a28c6af861c66","analyzedAt":"2026-09-13T01:50:10.254Z","contentChangedAt":"2026-09-13T01:50:10.254Z","schemaVersion":2},"datasetVersion":"2026-09-20T03:17:13.778Z"}