time.Sleep(dur)
						attempts++
						continue
					}
					t.Errorf("unexpected error: %v", err)
					return
				}
			})
		})
	}
}

func TestDNSErrorUnwrap(t *testing.T) {
	if runtime.GOOS == "plan9" {
		// The Plan 9 implementation of the resolver doesn't use the Dial function yet. See https://go.dev/cl/409234
		t.Skip("skipping on plan9")
	}