anchor.diff:  
             %% Otherwise we must warn
             _ ->
  -            {{Name, _} = Pair, _} = Key,
  +            {{Name, _}, _} = Key,
   
               case not_underscored(Name) of
                 true ->
  -                IsShadowing = maps:is_key(Pair, ?key(E, current_vars)),
  -                Warn = {unused_var, Name, IsShadowing},
  +                Warn = {unused_var, Name},
                   elixir_errors:form_warn([{line, ClauseValue}], ?key(E, file), ?MODULE, Warn);
   
                 false ->
  
positive.code: %% UNUSED VARS
  
  check_unused_vars(#{unused_vars := Unused} = E) ->
    [elixir_errors:form_warn([{line, Line}], ?key(E, file), ?MODULE, {unused_var, Name, false}) ||
      {{{Name, _}, _}, Line} <- maps:to_list(Unused), Line /= false, not_underscored(Name)],
    E.
  
  
negative.code:     _ -> true
    end.
  
  format_error({unused_var, Name}) ->
    io_lib:format("variable \"~ts\" is unused (if the variable is not meant to be used, prefix it with an underscore)", [Name]).
  