Issue with OpenStruct in Ruby 2.3

[soylent]

Probably the recent changes in ostruct in ruby 2.3 cause the following problem:

require 'spec_helper'

describe 'rr ostruct err' do
  it 'fails' do
    open_struct = OpenStruct.new(foo: :bar)

    mock(open_struct).stubbed { 'stubbed_value' }
    open_struct.stubbed

    expect(open_struct.foo).to eq :bar # PASSES
    expect(open_struct.foo).to eq :bar # FAILS

    # Failures:
    #
    #   1) ostruct err fails
    #      Failure/Error: expect(open_struct.foo).to eq :bar # FAILS
    #      RR::Errors::DoubleNotFoundError:
    #        On subject #<OpenStruct foo=:bar>,
    #        unexpected method invocation:
    #          foo()
    #        expected invocations:
    #      # ./spec/ostruct_spec.rb:11:in `block (2 levels) in <top (required)>'
    #      # -e:1:in `<main>'
  end
end

Please also see the changes in ostruct: ruby/ruby@3bf9b2f