{"id":"2f2f02f35d182ba3","repo":"docker/cli","slug":"expected-a-map-or-a-list-got-t-v","errorCode":null,"errorMessage":"expected a map or a list, got %T: %#v","messagePattern":"expected a map or a list, got %T: %#v","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"cli/compose/loader/loader.go","lineNumber":847,"sourceCode":"\t\t\tfor i, allowSep := range allowSeps {\n\t\t\t\tentry := fmt.Sprint(entry)\n\t\t\t\tk, v, ok := strings.Cut(entry, allowSep)\n\t\t\t\tif ok {\n\t\t\t\t\t// Entry uses this allowed separator. Add it to the result, using\n\t\t\t\t\t// sep as a separator.\n\t\t\t\t\tresult = append(result, fmt.Sprintf(\"%s%s%s\", k, sep, v))\n\t\t\t\t\tbreak\n\t\t\t\t} else if i == len(allowSeps)-1 {\n\t\t\t\t\t// No more separators to try, keep the entry if allowNil.\n\t\t\t\t\tif allowNil {\n\t\t\t\t\t\tresult = append(result, k)\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t\treturn result\n\t}\n\tpanic(fmt.Errorf(\"expected a map or a list, got %T: %#v\", listOrMapping, listOrMapping))\n}\n\nfunc transformMappingOrListFunc(sep string, allowNil bool) TransformerFunc {\n\treturn func(data any) (any, error) {\n\t\treturn transformMappingOrList(data, sep, allowNil), nil\n\t}\n}\n\nfunc transformMappingOrList(mappingOrList any, sep string, allowNil bool) any {\n\tswitch values := mappingOrList.(type) {\n\tcase map[string]any:\n\t\treturn toMapStringString(values, allowNil)\n\tcase []any:\n\t\tresult := make(map[string]any)\n\t\tfor _, v := range values {\n\t\t\tkey, val, hasValue := strings.Cut(v.(string), sep)\n\t\t\tswitch {\n\t\t\tcase !hasValue && allowNil:","sourceCodeStart":829,"sourceCodeEnd":865,"githubUrl":"https://github.com/docker/cli/blob/e9452d6e785f6e365712b9d71bd7517591773c86/cli/compose/loader/loader.go#L829-L865","documentation":"Error \"expected a map or a list, got %T: %#v\" thrown in docker/cli.","triggerScenarios":"Thrown at cli/compose/loader/loader.go:847 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"analyzedSha":"e9452d6e785f6e365712b9d71bd7517591773c86","analyzedAt":"2026-08-01T07:09:22.474Z","schemaVersion":2}