larksuite/cli · error

unsupported charset %q

Error message

unsupported charset %q

What it means

encodeTextCharset: the draft's charset label is not UTF-8-like and htmlcharset.Lookup has no matching encoder, so the outgoing MIME part cannot be encoded; an intermediate error the mail command layer wraps into a typed ValidationError.

Source

Thrown at shortcuts/mail/draft/charset.go:52

func decodeTextCharset(body []byte, label string) ([]byte, error) {
	if isUTF8LikeCharset(label) {
		return body, nil
	}
	reader, err := htmlcharset.NewReaderLabel(label, bytes.NewReader(body))
	if err != nil {
		return nil, err
	}
	return io.ReadAll(reader)
}

func encodeTextCharset(body []byte, label string) ([]byte, error) {
	if isUTF8LikeCharset(label) {
		return body, nil
	}
	enc, _ := htmlcharset.Lookup(label)
	if enc == nil {
		return nil, fmt.Errorf("unsupported charset %q", label) //nolint:forbidigo // intermediate draft charset error; mail command layer wraps into typed ValidationError.
	}
	var buf bytes.Buffer
	writer := transform.NewWriter(&buf, enc.NewEncoder())
	if _, err := writer.Write(body); err != nil {
		_ = writer.Close()
		return nil, err
	}
	if err := writer.Close(); err != nil {
		return nil, err
	}
	return buf.Bytes(), nil
}

View on GitHub (pinned to 7fd6ef3c07)

Solutions

1. Use UTF-8 or another alias recognized by htmlcharset (e.g. gb18030, iso-8859-1)

When it happens

Trigger: Thrown at shortcuts/mail/draft/charset.go:52 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of larksuite/cli@7fd6ef3c07 (2026-09-04). Data as JSON: /api/errors/ca29b26f3fab26f0. Report an issue: GitHub.