ln1.Close()
				t.Fatal(err)
			}
			ln2, err := Listen(tt.network2, JoinHostPort(tt.address2, ln1.(*TCPListener).port()))
			if err == nil {
				ln2.Close()
			}
			if secondErr = checkDualStackSecondListener(tt.network2, tt.address2, err, tt.xerr); secondErr != nil {
				ln1.Close()
				continue
			}
			ln1.Close()
			break
		}
		if firstErr != nil {
			t.Error(firstErr)
		}