ipfs/kubo · error

failure to decode config: %w

Error message

failure to decode config: %w

What it means

FromMap re-encodes a generic map through JSON into a typed Config, and the decode step failed. This means the map's shape or value types do not match the config schema (unknown/wrong-typed fields), e.g. when SetConfigKey writes a value the Config struct cannot accept. %w carries the json.Decoder error.

Source

Thrown at config/config.go:130

		return []byte(strings.Trim(s, "\n")), nil
	}
	return Marshal(value)
}

// Marshal configuration with JSON.
func Marshal(value any) ([]byte, error) {
	// need to prettyprint, hence MarshalIndent, instead of Encoder
	return json.MarshalIndent(value, "", "  ")
}

func FromMap(v map[string]any) (*Config, error) {
	buf := new(bytes.Buffer)
	if err := json.NewEncoder(buf).Encode(v); err != nil {
		return nil, err
	}
	var conf Config
	if err := json.NewDecoder(buf).Decode(&conf); err != nil {
		return nil, fmt.Errorf("failure to decode config: %w", err)
	}
	return &conf, nil
}

func ToMap(conf *Config) (map[string]any, error) {
	buf := new(bytes.Buffer)
	if err := json.NewEncoder(buf).Encode(conf); err != nil {
		return nil, err
	}
	var m map[string]any
	if err := json.NewDecoder(buf).Decode(&m); err != nil {
		return nil, fmt.Errorf("failure to decode config: %w", err)
	}
	return m, nil
}

// Convert config to a map, without using encoding/json, since
// zero/empty/'omitempty' fields are excluded by encoding/json during

View on GitHub (pinned to 329838acdf)

Solutions

1. Check the key path and value type against docs/config.md and retry the config write
2. Inspect the wrapped JSON error for the offending field name
3. Fix the stored config file if it is already corrupt (restore a backup or re-init)

When it happens

Trigger: Thrown at config/config.go:130 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ipfs/kubo@329838acdf (2026-09-03). Data as JSON: /api/errors/c7cda1ae40de2273. Report an issue: GitHub.