larksuite/cli · error

unsupported content-range: %q

Error message

unsupported content-range: %q

What it means

parseContentRange validates an HTTP Content-Range header returned by the server during a partial (resumable) download. This error means the header did not start with a 'bytes' unit token (case-insensitive), so the range specification could not be interpreted. The library only supports the standard 'bytes' unit defined by RFC 7233.

Source

Thrown at extension/download/download.go:679

	total int64
}

func (cr contentRange) String() string {
	return fmt.Sprintf("bytes %d-%d/%d", cr.start, cr.end, cr.total)
}

func (cr contentRange) length() int64 {
	return cr.end - cr.start + 1
}

func parseContentRange(header string) (contentRange, error) {
	header = strings.TrimSpace(header)
	if header == "" {
		return contentRange{}, fmt.Errorf("content-range is empty")
	}
	unit, spec, found := strings.Cut(header, " ")
	if !found || !strings.EqualFold(unit, "bytes") {
		return contentRange{}, fmt.Errorf("unsupported content-range: %q", header)
	}
	parts := strings.SplitN(strings.TrimSpace(spec), "/", 2)
	if len(parts) != 2 || parts[0] == "" || parts[1] == "" || parts[0] == "*" {
		return contentRange{}, fmt.Errorf("unsupported content-range: %q", header)
	}
	if parts[1] == "*" {
		return contentRange{}, fmt.Errorf("unknown total size in content-range: %q", header)
	}
	bounds := strings.SplitN(parts[0], "-", 2)
	if len(bounds) != 2 || bounds[0] == "" || bounds[1] == "" {
		return contentRange{}, fmt.Errorf("unsupported content-range: %q", header)
	}
	start, err := strconv.ParseInt(bounds[0], 10, 64)
	if err != nil {
		return contentRange{}, fmt.Errorf("parse range start: %w", err)
	}
	end, err := strconv.ParseInt(bounds[1], 10, 64)
	if err != nil {

View on GitHub (pinned to 7fd6ef3c07)

Solutions

1. Inspect the raw Content-Range header the server returns (curl -I or a debug proxy) and confirm it begins with 'bytes '.
2. Fix or remove the proxy/CDN layer that is rewriting the header.
3. If the server genuinely uses a non-bytes unit, download the resource without range requests (single full GET) instead of the partial-download path.
4. Update the library/endpoint configuration so downloads go to a compliant endpoint.

Example fix

// before (server sends)
// Content-Range: items 0-9/50
// after (required by this library)
// Content-Range: bytes 0-9/50

func validContentRange(h string) bool {
	unit, spec, ok := strings.Cut(h, " ")
	return ok && strings.EqualFold(unit, "bytes") && strings.Contains(spec, "/")
}
// check resp.Header.Get("Content-Range") before resuming

cr, err := parseContentRange(header)
if err != nil {
	return fmt.Errorf("server sent non-bytes Content-Range %q: %w", header, err)
}

When it happens

Trigger: openPartial or openNext received a 206/multi-range response whose Content-Range header is missing the 'bytes ' prefix, uses another unit like 'items 0-9/50', or has no space separator at all (e.g. 'bytes0-99/100').

Common situations: A proxy or CDN rewrites or strips the Content-Range unit; a non-Lark storage endpoint behind a custom base URL returns ranges in a non-byte unit; a broken/misbehaving server sends a malformed header with no space after the unit.

Related errors

• unknown total size in content-range: %q
• parse range start: %w
• parse range end: %w
• parse total size: %w
• invalid total size: %d

AI-assisted analysis of larksuite/cli@7fd6ef3c07 (2026-09-04). Data as JSON: /api/errors/c8f3716fddc7fc32. Report an issue: GitHub.