Methods cannot be invoked from within list comprehensions

works fine:

class A
  def bar(x)
    foo(x)

  def foo(y)
    y

fails to load:

class A
  def bar(x)
    [foo(z) | z in x]

  def foo(y)
    y

>> load('issue.re')
.:2: variable '___instance_variables_1' is unbound
exception throw: {error,[{".",
                          [{2,erl_lint,
                            {unbound_var,'___instance_variables_1'}}]}],
                        []}
  in function  reia_module:build/2
  in call from erl_eval:do_apply/5
  in call from eval_shim:exprs/3
  in call from reia_erl:erl_funcall/3
  in call from 'Eval':exprs/2
  in call from 'Eval':string/1
  in call from 'Main':load/1
  in call from 'Eval':local/2