Allow custom fields in Exception.t typespec

Author: ericmj

lib/elixir/lib/exception.ex

@@ -15,7 +15,11 @@ defmodule Exception do
   """
 
   @typedoc "The exception type"
-  @type t :: %{__struct__: module, __exception__: true}
+  @type t :: %{
+    required(:__struct__) => module,
+    required(:__exception__) => true,
+    atom => any
+  }
 
   @typedoc "The kind handled by formatting functions"
   @type kind :: :error | :exit | :throw | {:EXIT, pid}