Dialyxir.Warnings.CallbackSpecTypeMismatch (Dialyxir v1.4.4) View Source
The return type in the @spec does not match the expected return type of the behaviour.
Example
defmodule ExampleBehaviour do
@callback ok(:ok) :: :ok
end
defmodule Example do
@behaviour ExampleBehaviour
@spec ok(:ok) :: :error
def ok(:ok) do
:error
end
end