Timex - использование datetime с миграцией

Question

У меня есть следующий модуль:

defmodule SoundButtonsApi.Accounts.Session do
  use Ecto.Schema
  use Timex
  import Ecto.Changeset

  schema "accounts_sessions" do
    field :expires_at, Timex.Ecto.DateTime, null: false
    field :token, :string, null: false
    field :user_id, :id, null: false

    timestamps()
  end

  def changeset(model, params \\ :empty) do
    model
    |> cast(params, [:user_id])
    |> set_token()
    |> set_expires_at()
    |> validate_required([:user_id, :token, :expires_at])
  end

  defp set_token(changeset) do
    put_change(changeset, :token, UUID.uuid4())
  end

  defp set_expires_at(changeset) do
    put_change(changeset, :expires_at, Timex.shift(Timex.now(), days: 1))
  end
end

и связанная миграция:

defmodule SoundButtonsApi.Repo.Migrations.CreateSoundButtonsApi.Accounts.Session do
  use Ecto.Migration

  def change do
    create table(:accounts_sessions) do
      add :token, :string
      add :expires_at, :utc_datetime
      add :user_id, references(:accounts_users, on_delete: :nothing)

      timestamps()
    end

    create index(:accounts_sessions, [:user_id])
    create index(:accounts_sessions, [:token])
  end
end

Но любая попытка вставки приведет к следующей ошибке: (CaseClauseError) no case clause matching: {{{2017, 4, 8}, {10, 8, 58, 947735}}}

Есть идеи, как это исправить?

Я использую версии 3.1 как timex, так и timex_ecto.

РЕДАКТИРОВАТЬ: полный стек трассировки ошибки:

 stacktrace:
   (ecto) lib/ecto/adapters/postgres/datetime.ex:40: Ecto.Adapters.Postgres.TypeModule.encode_params/3
   (postgrex) lib/postgrex/query.ex:45: DBConnection.Query.Postgrex.Query.encode/3
   (db_connection) lib/db_connection.ex:1071: DBConnection.describe_run/5
   (db_connection) lib/db_connection.ex:1142: anonymous fn/4 in DBConnection.run_meter/5
   (db_connection) lib/db_connection.ex:1199: DBConnection.run_begin/3
   (db_connection) lib/db_connection.ex:584: DBConnection.prepare_execute/4
   (ecto) lib/ecto/adapters/postgres/connection.ex:93: Ecto.Adapters.Postgres.Connection.execute/4
   (ecto) lib/ecto/adapters/sql.ex:243: Ecto.Adapters.SQL.sql_call/6
   (ecto) lib/ecto/adapters/sql.ex:562: Ecto.Adapters.SQL.struct/7
   (ecto) lib/ecto/repo/schema.ex:467: Ecto.Repo.Schema.apply/4
   (ecto) lib/ecto/repo/schema.ex:205: anonymous fn/13 in Ecto.Repo.Schema.do_insert/4
   (sound_buttons_api) lib/sound_buttons_api/web/controllers/session_controller.ex:26: SoundButtonsApi.Web.SessionController.create/2
   (sound_buttons_api) lib/sound_buttons_api/web/controllers/session_controller.ex:1: SoundButtonsApi.Web.SessionController.action/2
   (sound_buttons_api) lib/sound_buttons_api/web/controllers/session_controller.ex:1: SoundButtonsApi.Web.SessionController.phoenix_controller_pipeline/2
   (sound_buttons_api) lib/sound_buttons_api/web/endpoint.ex:1: SoundButtonsApi.Web.Endpoint.instrument/4
   (phoenix) lib/phoenix/router.ex:277: Phoenix.Router.__call__/1
   (sound_buttons_api) lib/sound_buttons_api/web/endpoint.ex:1: SoundButtonsApi.Web.Endpoint.plug_builder_call/2
   (sound_buttons_api) lib/sound_buttons_api/web/endpoint.ex:1: SoundButtonsApi.Web.Endpoint.call/2
   (phoenix) lib/phoenix/test/conn_test.ex:224: Phoenix.ConnTest.dispatch/5
   test/web/controllers/session_controller_test.exs:21: (test)

РЕДАКТИРОВАТЬ 2: виновный (?) Код:

def create(conn, %{"user" => user_params}) do
    user = Repo.get_by!(SoundButtonsApi.Accounts.User, email: user_params["email"])
    with {:ok, %Session{} = session} <- Accounts.create_session(%{user_id: user.id}) do # line 26
      conn
      |> put_status(:created)
      |> put_resp_header("location", session_path(conn, :show, session))
      |> render("show.json", session: session)
    end
  end

И создать_сессион:

  def create_session(attrs \\ %{}) do
    %Session{}
    |> Session.changeset(attrs)
    |> Repo.insert()
  end