res.Listeners = append(res.Listeners, listeners[i])
		res.Mux = append(res.Mux, m)
	}
	close(ready)
	for _, m := range res.Managers {
		for _, remote := range m.Targets() {
			if err := m.Connection(remote).WaitForConnect(ctx); err != nil {
				return nil, err
			}
		}
	}
	return &res, nil
}

// Cleanup will clean up the test grid.
func (t *TestGrid) Cleanup() {
	t.cancel()
	t.cleanupOnce.Do(func() {