This related to my other question, but I’m asking a new one for clarity.

Using the built-in validation_confirmation I’m getting:
undefined function validate_confirmation/4.

It’s an Ecto(?) function, so I’m stumped on this one. None of the other functions there fail, only validation_confirmation. Am I missing an import somewhere? Undefined error makes no sense here.

defp validate_email(changeset) do
    IO.inspect(changeset)
    changeset
    |> validate_required([:email])
    |> validate_format(:email, ~r/^[^\s]+@[^\s]+$/, message: "must have the @ sign and no spaces")
    |> validate_length(:email, max: 160)
    |> unsafe_validate_unique(:email, TurnStile.Repo)
    |> unique_constraint(:email)
    |> validate_confirmation(changeset, :password, message: "does not match password")
  end