{"record":{"id":"f9b753ce4762b577","repo":"hyperledger/fabric","slug":"failed-writing-file-s-v","errorCode":null,"errorMessage":"failed writing file %s: %v","messagePattern":"failed writing file (.+?): (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"cmd/common/config.go","lineNumber":50,"sourceCode":"\n\tif err := yaml.Unmarshal(configData, &config); err != nil {\n\t\treturn Config{}, errors.Errorf(\"error unmarshalling YAML file %s: %s\", file, err)\n\t}\n\n\treturn config, validateConfig(config)\n}\n\n// ToFile writes the config into a file\nfunc (c Config) ToFile(file string) error {\n\tif err := validateConfig(c); err != nil {\n\t\treturn errors.Wrap(err, \"config isn't valid\")\n\t}\n\tb, err := yaml.Marshal(c)\n\tif err != nil {\n\t\treturn errors.Wrap(err, \"failed to marshal config\")\n\t}\n\tif err := os.WriteFile(file, b, 0o600); err != nil {\n\t\treturn errors.Errorf(\"failed writing file %s: %v\", file, err)\n\t}\n\treturn nil\n}\n\nfunc validateConfig(conf Config) error {\n\tnonEmptyElems := map[string]string{\n\t\t\"MSPID\":        conf.SignerConfig.MSPID,\n\t\t\"IdentityPath\": conf.SignerConfig.IdentityPath,\n\t\t\"KeyPath\":      conf.SignerConfig.KeyPath,\n\t}\n\n\tfor key, value := range nonEmptyElems {\n\t\tif value == \"\" {\n\t\t\treturn errors.Errorf(\"%s is mandatory and cannot be empty\", key)\n\t\t}\n\t}\n\n\treturn nil","sourceCodeStart":32,"sourceCodeEnd":68,"githubUrl":"https://github.com/hyperledger/fabric/blob/2736b63f8fd5932511d56fe68b7039d15977f7f6/cmd/common/config.go#L32-L68","documentation":"ToFile serializes the Config struct to YAML and writes it to disk with os.WriteFile (mode 0600). This error wraps the os.WriteFile failure, meaning the YAML marshal succeeded but the file write itself failed. The library throws it so callers get a clear message identifying both the target path and the underlying OS error.","triggerScenarios":"Calling Config.ToFile (directly or via persistConfig) when the target path is in a non-existent directory, the process lacks write permission, the path is a directory, or the disk is full.","commonSituations":"Persisting config to ~/.fabric/... before the directory exists; read-only filesystem or container volume; running as non-root user while writing to a root-owned path; typo'd or empty file path.","solutions":["Create the parent directory first (os.MkdirAll(filepath.Dir(file), 0o755)) before calling ToFile","Verify the process has write permission on the target path (check ownership, run as correct user)","Confirm the path is a file, not a directory, and the disk isn't full","Inspect the wrapped %v OS error for the exact errno"],"exampleFix":"// before\nif err := conf.ToFile(\"/etc/fabric/config.yaml\"); err != nil { ... }\n// after\nos.MkdirAll(\"/etc/fabric\", 0o755)\nif err := conf.ToFile(\"/etc/fabric/config.yaml\"); err != nil { log.Fatal(err) }","handlingStrategy":"validation","validationCode":"info, err := os.Stat(file)\nif err != nil || info.IsDir() {\n    return fmt.Errorf(\"cannot write config to %s\", file)\n}\nif err := os.MkdirAll(filepath.Dir(file), 0o755); err != nil {\n    return err\n}","typeGuard":"func writablePath(p string) bool {\n    info, err := os.Stat(filepath.Dir(p))\n    return err == nil && info.IsDir()\n}","tryCatchPattern":"if err := conf.ToFile(path); err != nil {\n    var pe *os.PathError\n    if errors.As(err, &pe) { log.Printf(\"write failed at %s: %v\", pe.Path, pe.Err) }\n}","preventionTips":["Always MkdirAll the parent directory before ToFile","Use mode 0600 paths under the current user's home or an explicitly writable dir","Check disk space in automation before persisting","Never pass a directory path as the target file"],"tags":["filesystem","io","config"],"backgroundTag":"file-write-failed","analyzedSha":"2736b63f8fd5932511d56fe68b7039d15977f7f6","analyzedAt":"2026-09-04T08:52:36.465Z","contentChangedAt":"2026-09-04T08:52:36.465Z","schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}