assert fails with error on pattern matching with struct type

[vheathen]

Environment

• Elixir & Erlang/OTP versions:
  Erlang/OTP 22 [erts-10.7] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [hipe]
  Elixir 1.10.2 (compiled with Erlang/OTP 22)

• Operating system:
  Ubuntu 18.04 in Windows 10 WSL2

Current behavior

defmodule TestTest do
  use ExUnit.Case

  defmodule T do
    defstruct [:id, :attached]
  end

  setup do
    t = %T{id: 123, attached: false}

    [t: t]
  end

  test "fails without error", %{t: %{id: id} = t} do
    assert %{uuid: ^id, attached: true} = %T{
             attached: false,
             id: 321
           }
  end

  test "fails with error 1", %{t: %type{id: id}} do
    assert %{__struct__: ^type, uuid: ^id, attached: true} = %T{
             attached: false,
             id: 321
           }
  end

  test "fails with error  2", %{t: %type{id: id}} do
    assert %^type{uuid: ^id, attached: true} = %T{
             attached: false,
             id: 321
           }
  end

  test "fails with error 3", %{t: %{id: id}} do
    # type variable isn't pinned
    assert %_type{uuid: ^id, attached: true} = %T{
             attached: false,
             id: 321
           }
  end

end

"fails with error 1" gives:

** (EXIT from #PID<0.94.0>) exited in: GenServer.stop(#PID<0.362.0>, :normal, :infinity)
    ** (EXIT) exited in: :sys.terminate(#PID<0.362.0>, :normal, :infinity)
        ** (EXIT) an exception was raised:
            ** (FunctionClauseError) no function clause matching in Code.ensure_loaded?/1
                (elixir 1.10.2) lib/code.ex:1233: Code.ensure_loaded?({:^, [line: 22], [{:type, [line: 22], nil}]})
                (ex_unit 1.10.2) lib/ex_unit/diff.ex:677: ExUnit.Diff.load_struct/1
                (ex_unit 1.10.2) lib/ex_unit/diff.ex:630: ExUnit.Diff.diff_quoted_struct/4
                (elixir 1.10.2) lib/task/supervised.ex:90: Task.Supervised.invoke_mfa/2
                (elixir 1.10.2) lib/task/supervised.ex:35: Task.Supervised.reply/5
                (stdlib 3.12) proc_lib.erl:249: :proc_lib.init_p_do_apply/3

"fails with error" 2 and 3 give an another error:

 ** (EXIT from #PID<0.94.0>) exited in: GenServer.stop(#PID<0.362.0>, :normal, :infinity)
    ** (EXIT) exited in: :sys.terminate(#PID<0.362.0>, :normal, :infinity)
        ** (EXIT) an exception was raised:
            ** (FunctionClauseError) no function clause matching in Code.Identifier.inspect_as_atom/1
                (elixir 1.10.2) lib/code/identifier.ex:135: Code.Identifier.inspect_as_atom({:type, [line: 36], nil})
                (ex_unit 1.10.2) lib/ex_unit/diff.ex:903: ExUnit.Diff.safe_to_algebra/2
                (ex_unit 1.10.2) lib/ex_unit/diff.ex:1006: ExUnit.Diff.wrap_on_diff/3
                (ex_unit 1.10.2) lib/ex_unit/formatter.ex:377: ExUnit.Formatter.format_sides/6
                (ex_unit 1.10.2) lib/ex_unit/formatter.ex:365: ExUnit.Formatter.format_context/4
                (ex_unit 1.10.2) lib/ex_unit/formatter.ex:158: ExUnit.Formatter.format_assertion_error/6
                (ex_unit 1.10.2) lib/ex_unit/formatter.ex:190: ExUnit.Formatter.format_kind_reason/6
                (ex_unit 1.10.2) lib/ex_unit/formatter.ex:130: anonymous fn/7 in ExUnit.Formatter.format_test_failure/5
                (elixir 1.10.2) lib/enum.ex:1495: anonymous fn/2 in Enum.map_join/3
                (elixir 1.10.2) lib/enum.ex:3359: Enum.map_intersperse_list/3
                (elixir 1.10.2) lib/enum.ex:1495: Enum.map_join/3
                (ex_unit 1.10.2) lib/ex_unit/formatter.ex:129: ExUnit.Formatter.format_test_failure/5
                (ex_unit 1.10.2) lib/ex_unit/cli_formatter.ex:99: ExUnit.CLIFormatter.handle_cast/2
                (stdlib 3.12) gen_server.erl:637: :gen_server.try_dispatch/4
                (stdlib 3.12) gen_server.erl:711: :gen_server.handle_msg/6
                (stdlib 3.12) proc_lib.erl:249: :proc_lib.init_p_do_apply/3

Expected behavior

Tests should fail but without crashing the test suit.