JuliusBrussee/caveman · error

proposalrun: detail contains trailing data: %w

Error message

proposalrun: detail contains trailing data: %w

What it means

Error "proposalrun: detail contains trailing data: %w" thrown in JuliusBrussee/caveman.

Source

Thrown at shared/platform/proposalrun/proposalrun.go:71

// reject values that could not be persisted there before allocating output.
// The decoder enforces the JSON number grammar (including rejecting NaN/Inf),
// and a second decode below rejects any trailing value or non-whitespace data.
func CanonicalDetail(detail json.RawMessage) ([]byte, error) {
	if len(detail) == 0 {
		return []byte("{}"), nil
	}
	var v any
	dec := json.NewDecoder(bytes.NewReader(detail))
	dec.UseNumber()
	if err := dec.Decode(&v); err != nil {
		return nil, fmt.Errorf("proposalrun: detail is not valid JSON: %w", err)
	}
	var trailing any
	if err := dec.Decode(&trailing); err != io.EOF {
		if err == nil {
			return nil, fmt.Errorf("proposalrun: detail contains trailing JSON")
		}
		return nil, fmt.Errorf("proposalrun: detail contains trailing data: %w", err)
	}
	v, err := canonicalizeJSONValue(v)
	if err != nil {
		return nil, fmt.Errorf("proposalrun: canonicalize detail: %w", err)
	}
	out, err := json.Marshal(v)
	if err != nil {
		return nil, fmt.Errorf("proposalrun: marshal canonical detail: %w", err)
	}
	return out, nil
}

// PostgreSQL jsonb stores JSON numbers using its numeric type. These are the
// documented numeric bounds (131072 digits before and 16383 after the decimal
// point); rejecting at the canonicalization boundary keeps write and read-back
// hashing deterministic and avoids unbounded strings from hostile exponents.
// maxJSONBNumberExponent is an additional allocation guard. PostgreSQL can
// accept some zero literals with a larger positive exponent after normalizing

View on GitHub (pinned to 27d5a3981a)

Solutions

1. Remove trailing data from the detail payload.

When it happens

Trigger: Thrown at shared/platform/proposalrun/proposalrun.go:71 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of JuliusBrussee/caveman@27d5a3981a (2026-08-15). Data as JSON: /api/errors/3c669d6a6671bd65. Report an issue: GitHub.