RSpec 2.7.0: Problem with full_description

a_spec.rb

describe 'A' do
  describe '#foo' do
    it 'is generally okay' do; end

    describe 'subconcern' do
      it 'has common behavior' do; end

      describe 'case 1' do
        it 'does the right thing' do; end
      end
    end
  end
end

debug_formatter.rb

require 'rspec/core/formatters/base_formatter'

class DebugFormatter < ::RSpec::Core::Formatters::BaseFormatter
  def start(*args)
    super

    STDOUT.puts "rspec-core #{RSpec::Core::Version::STRING}"
  end

  def example_started(example)
    super

    STDOUT.puts "Example: #{example.full_description.inspect}"
  end

  def example_group_started(example_group)
    super

    STDOUT.puts "  Group: #{example_group.metadata[:example_group][:full_description].inspect}"
  end
end

output.txt

$ rspec _2.6.4_ -I. -f DebugFormatter a_spec.rb 
rspec-core 2.6.4
  Group: "A"
  Group: "A#foo"
Example: "A#foo is generally okay"
  Group: "A#foo subconcern"
Example: "A#foo subconcern has common behavior"
  Group: "A#foo subconcern case 1"
Example: "A#foo subconcern case 1 does the right thing"
$ rspec _2.7.0_ -I. -f DebugFormatter a_spec.rb 
rspec-core 2.7.0
  Group: "A"
  Group: "A#foo"
Example: "A#foo is generally okay"
  Group: "A A#foo subconcern"
Example: "A A#foo subconcern has common behavior"
  Group: "A A#foo A A#foo subconcern case 1"
Example: "A A#foo A A#foo subconcern case 1 does the right thing"