Dializer failed pattern match in 'case' clause in 'with' clause

[ByeongUkChoi]

Precheck

• Take a look at the open issues and be sure that your issue is not already covered.
• Be sure your versions of Dialyxir and Erlex are up to date.

Environment

• Elixir & Erlang/OTP versions (elixir --version): 1.13.4

• Which version of Dialyxir are you using? (cat mix.lock | grep dialyxir): 1.2.0

Current behavior

• Describe current behavior. Include errors, stack traces, and any additional information that might be important here.

dializer succeeds in Foo.test_1/0 But Foo.test_2/0 failed

defmodule Foo do
  def test_1() do
    with {:ok, _} <- aa(),
         {:ok, _} <- bb(),
         {:ok, _} <- cc() do
      :success
    else
      nil -> :error_c
      {:error, _} -> :error_a
      {:error, _, _} -> :error_b
    end
  end

  def test_2() do
    with {:ok, _} <- aa(),
         {:ok, _} <- bb(),
         {:ok, _} <- cc() do
      :success
    else
      nil ->
        :error_c

      err ->
        case err do
          {:error, _} -> :error_a
          {:error, _, _} -> :error_b
        end
    end
  end

  defp aa() do
    if Enum.random(0..1) == 1 do
      {:ok, 1}
    else
      {:error, 2}
    end
  end

  defp bb() do
    if Enum.random(0..1) == 1 do
      {:ok, 3}
    else
      {:error, 4, 5}
    end
  end

  defp cc() do
    if Enum.random(0..1) == 1 do
      {:ok, 6}
    else
      nil
    end
  end
end

Expected behavior

• A short description of the expected behavior.

Everyone needs to succeed. all functions(test_1, test_2) work successfully.