{"record":{"id":"20901d4b4546d0e8","repo":"apache/beam","slug":"unexpected-param-kind-v","errorCode":null,"errorMessage":"unexpected param kind: %v","messagePattern":"unexpected param kind: (.+?)","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"sdks/go/pkg/beam/core/graph/bind.go","lineNumber":221,"sourceCode":"\n\t\t\t\tkind = Iter\n\t\t\t\tother = typex.New(trimmed[0])\n\n\t\t\tcase funcx.FnReIter:\n\t\t\t\tvalues, _ := funcx.UnfoldReIter(args[0].T)\n\t\t\t\ttrimmed := trimIllegal(values)\n\t\t\t\tif len(trimmed) != 1 {\n\t\t\t\t\treturn nil, kind, errors.Errorf(\"%v cannot bind to %v\", t, args[0])\n\t\t\t\t}\n\n\t\t\t\tkind = ReIter\n\t\t\t\tother = typex.New(trimmed[0])\n\n\t\t\tcase funcx.FnMultiMap:\n\t\t\t\treturn nil, kind, errors.Errorf(\"input to MultiMap side input must be KV, got %v\", t)\n\n\t\t\tdefault:\n\t\t\t\treturn nil, kind, errors.Errorf(\"unexpected param kind: %v\", arg)\n\t\t\t}\n\t\t}\n\tcase typex.Composite:\n\t\tswitch t.Type() {\n\t\tcase typex.KVType:\n\t\t\tif isMain {\n\t\t\t\tif args[0].Kind != funcx.FnValue {\n\t\t\t\t\treturn nil, kind, errors.Errorf(\"key of %v cannot bind to %v\", t, args[0])\n\t\t\t\t}\n\t\t\t\tif args[1].Kind != funcx.FnValue {\n\t\t\t\t\treturn nil, kind, errors.Errorf(\"value of %v cannot bind to %v\", t, args[1])\n\t\t\t\t}\n\t\t\t\tother = typex.NewKV(typex.New(args[0].T), typex.New(args[1].T))\n\t\t\t} else {\n\t\t\t\tswitch args[0].Kind {\n\t\t\t\tcase funcx.FnIter:\n\t\t\t\t\tvalues, _ := funcx.UnfoldIter(args[0].T)\n\t\t\t\t\ttrimmed := trimIllegal(values)","sourceCodeStart":203,"sourceCodeEnd":239,"githubUrl":"https://github.com/apache/beam/blob/12126d8942aaf848030c478b4c6a28c6af861c66/sdks/go/pkg/beam/core/graph/bind.go#L203-L239","documentation":"Defensive guard in tryBindInbound's default branch: the side-input parameter's funcx kind is none of the known cases (FnValue, FnIter, FnReIter, FnMultiMap). Because the switch above exhausts all exported ParamKinds for side inputs, hitting this means an unrecognized ParamKind value — effectively a Beam library/registration bug rather than a user pipeline error.","triggerScenarios":"Thrown at sdks/go/pkg/beam/core/graph/bind.go:221 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Report a Beam bug with the DoFn signature that triggers it","Verify Beam SDK versions match across the pipeline (no mixed-version registrations)"],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"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"}