{"record":{"id":"511cdcc4619cfc17","repo":"go-delve/delve","slug":"could-not-load-swiss-map-group-elems-v","errorCode":null,"errorMessage":"could not load swiss map group elems: %v","messagePattern":"could not load swiss map group elems: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/proc/mapiter.go","lineNumber":688,"sourceCode":"\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\nfunc (it *mapIteratorSwiss) key() *Variable {\n\treturn it.curKey\n}\n\nfunc (it *mapIteratorSwiss) value() *Variable {","sourceCodeStart":670,"sourceCodeEnd":706,"githubUrl":"https://github.com/go-delve/delve/blob/a23773e6c31361e43246bc43a424ee009679b174/pkg/proc/mapiter.go#L670-L706","documentation":"Set on a map Variable by loadCurrentGroup when, in the split-group representation, the 'elems' array field of the group cannot be resolved from DWARF. Delve throws it because, alongside keys, the elems field is required to retrieve map values in split-group swiss maps.","triggerScenarios":"Iterating a split-group swiss map where group.toField(it.groupFieldElems) fails: the group DWARF type lacks 'elems' or the field's type can't be read, typically from a Go runtime/Delve layout mismatch.","commonSituations":"Target built with a Go version whose internal/runtime/maps group struct differs; debugging with an outdated Delve; minimized or stripped binaries losing field metadata.","solutions":["Update Delve to a version supporting your Go toolchain's swiss map layout","Rebuild with default debug flags and a supported Go version","Verify debug info presence (go tool nm / readelf --debug-dump) on the binary","Fall back to application-level logging of the map"],"exampleFix":null,"handlingStrategy":"type-guard","validationCode":"if v.Unreadable != nil { return } // split-group elems field unresolvable","typeGuard":"func ok(v *proc.Variable) bool { return v != nil && v.Unreadable == nil }","tryCatchPattern":"if err := v.Unreadable; err != nil { log.Warnf(\"cannot read map values: %v\", err); return }","preventionTips":["Rebuild targets with a Delve-supported Go toolchain","Preserve DWARF (no -w -s, no strip) in debug builds","Upgrade Delve when adopting new Go releases","Handle Unreadable explicitly in every variable display path"],"tags":["go","debugger","dwarf","swiss-map"],"backgroundTag":"swiss-map-layout-mismatch","analyzedSha":"a23773e6c31361e43246bc43a424ee009679b174","analyzedAt":"2026-08-31T15:12:45.221Z","schemaVersion":2},"datasetVersion":"2026-08-31T22:30:34.772Z"}