jackc/pgx · error

pipeline: %s: received unexpected message type %T

Error message

pipeline: %s: received unexpected message type %T

What it means

Error "pipeline: %s: received unexpected message type %T" thrown in jackc/pgx.

Source

Thrown at pgconn/pgconn.go:2934

	for {
		msg, err := p.conn.receiveMessage()
		if err != nil {
			p.err = err
			p.conn.asyncClose()
			return nil, normalizeTimeoutError(p.ctx, err)
		}

		switch msg := msg.(type) {
		case *pgproto3.ParameterStatus, *pgproto3.NoticeResponse, *pgproto3.NotificationResponse:
			// Filter these message types out in pipeline mode. The normal processing is handled by PgConn.receiveMessage.
		default:
			return msg, nil
		}
	}
}

func (p *Pipeline) handleUnexpectedMessage(errStr string, msg pgproto3.BackendMessage) error {
	p.err = fmt.Errorf("pipeline: %s: received unexpected message type %T", errStr, msg)
	p.conn.asyncClose()
	return p.err
}

// Close closes the pipeline and returns the connection to normal mode.
func (p *Pipeline) Close() error {
	if p.closed {
		return p.err
	}

	p.closed = true

	if p.state.PendingSync() {
		p.conn.asyncClose()
		p.err = errors.New("pipeline has unsynced requests")
		p.conn.contextWatcher.Unwatch()
		p.conn.unlock()

View on GitHub (pinned to ec1a0befd2)

When it happens

Trigger: Thrown at pgconn/pgconn.go:2934 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of jackc/pgx@ec1a0befd2 (2026-08-04). Data as JSON: /data/errors/83835967982c9a1f.json. Report an issue: GitHub.