{"record":{"id":"df7049b4dfdd8a66","repo":"go-delve/delve","slug":"could-not-load-swiss-map-group-keys-v","errorCode":null,"errorMessage":"could not load swiss map group keys: %v","messagePattern":"could not load swiss map group keys: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/proc/mapiter.go","lineNumber":683,"sourceCode":"\tg := &swissGroup{}\n\n\tvar err2 error\n\tctrl, err2 := group.toField(it.groupFieldCtrl)\n\tif err2 != nil {\n\t\tit.v.Unreadable = fmt.Errorf(\"could not load swiss map group ctrl: %v\", err2)\n\t\treturn\n\t}\n\tg.ctrls = make([]byte, ctrl.DwarfType.Size())\n\t_, err = ctrl.mem.ReadMemory(g.ctrls, ctrl.Addr)\n\tif err != nil {\n\t\tit.v.Unreadable = err\n\t\treturn\n\t}\n\n\tif it.mapsplitgroup {\n\t\tg.keys, err2 = group.toField(it.groupFieldKeys)\n\t\tif err2 != nil {\n\t\t\tit.v.Unreadable = fmt.Errorf(\"could not load swiss map group keys: %v\", err2)\n\t\t\treturn\n\t\t}\n\t\tg.elems, err2 = group.toField(it.groupFieldElems)\n\t\tif err2 != nil {\n\t\t\tit.v.Unreadable = fmt.Errorf(\"could not load swiss map group elems: %v\", err2)\n\t\t\treturn\n\t\t}\n\t} else {\n\t\tg.slots, err2 = group.toField(it.groupFieldSlots)\n\t\tif err2 != nil {\n\t\t\tit.v.Unreadable = fmt.Errorf(\"could not load swiss map group slots: %v\", err2)\n\t\t\treturn\n\t\t}\n\t}\n\n\tit.group = g\n}\n","sourceCodeStart":665,"sourceCodeEnd":701,"githubUrl":"https://github.com/go-delve/delve/blob/a23773e6c31361e43246bc43a424ee009679b174/pkg/proc/mapiter.go#L665-L701","documentation":"Set on a map Variable by loadCurrentGroup for swiss maps using the split-group (SwissMapGroupKindSplit) representation: the 'keys' array field of the group could not be resolved from DWARF. Delve throws it because it cannot access key storage without the keys field when the map stores keys and elems in separate arrays.","triggerScenarios":"Iterating a large swiss map where groups are split (key/elem arrays separated for cache efficiency) and group.toField(it.groupFieldKeys) fails because the DWARF group type lacks a matching 'keys' field.","commonSituations":"Go version where split-group layout differs from Delve's expectation; binaries built with newer Go than the installed Delve supports; DWARF stripped or damaged by build/post-link flags.","solutions":["Upgrade Delve to the latest version matching your Go release","Rebuild the binary with full debug info (no -w -s)","Pin the Go toolchain to a Delve-supported version","Inspect map contents via program-side printing as a fallback"],"exampleFix":null,"handlingStrategy":"type-guard","validationCode":"if v.Unreadable != nil { return } // split-group keys field unresolvable; rebuild target or upgrade Delve","typeGuard":"func readable(v *proc.Variable) bool { return v != nil && v.Unreadable == nil }","tryCatchPattern":"if v.Unreadable != nil { return partialResult, v.Unreadable }","preventionTips":["Keep Delve and Go versions synchronized","Avoid obfuscation/minification tools on binaries destined for debugging","Verify group struct DWARF fields exist before large-map inspections","Always branch on Unreadable after map evaluation"],"tags":["go","debugger","dwarf","swiss-map"],"backgroundTag":"swiss-map-layout-mismatch","analyzedSha":"a23773e6c31361e43246bc43a424ee009679b174","analyzedAt":"2026-08-31T15:12:45.221Z","schemaVersion":2},"datasetVersion":"2026-08-31T19:17:28.585Z"}