Error in Bones plugin ann.rb: undefined method `empty?' for :desc:Symbol

A newbie to Ruby, running rake in the gem directory causes the following
error (Is it called a Stack trace? showing my Java background here). Any
help would be greatly appreciated…

rake aborted!
undefined method empty?' for :desc:Symbol /.rvm/gems/ruby-1.8.7-p371/gems/bones-3.8.0/lib/bones/plugins/ann.rb:25:ininitialize_ann’
/.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:318:in
instance_eval' /.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:318:ininitialize’
/.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:304:in
new' /.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:304:inevaluate’
/.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:169:in
ann' /.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:197:insend
/.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:197:in
__send' /.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:190:inmethod_missing’
/.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:199:in
__send' /.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:336:inmethod_missing’
/.rvm/gems/ruby-1.8.7-p371/gems/bones-3.8.0/lib/bones/plugins/ann.rb:24:in
initialize_ann' /.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:318:ininstance_eval’
/.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:318:in
initialize' /.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:304:innew’
/.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:304:in
evaluate' /.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious/configuration.rb:44:infor’
/.rvm/gems/ruby-1.8.7-p371/gems/loquacious-1.9.1/lib/loquacious.rb:22:in
configuration_for' /.rvm/gems/ruby-1.8.7-p371/gems/bones-3.8.0/lib/bones.rb:73:inconfig’
/.rvm/gems/ruby-1.8.7-p371/gems/bones-3.8.0/lib/bones/plugins/ann.rb:22:in
initialize_ann' /.rvm/gems/ruby-1.8.7-p371/gems/little-plugger-1.1.3/lib/little-plugger.rb:178:insend’
/.rvm/gems/ruby-1.8.7-p371/gems/little-plugger-1.1.3/lib/little-plugger.rb:178:in
initialize_plugins' /.rvm/gems/ruby-1.8.7-p371/gems/little-plugger-1.1.3/lib/little-plugger.rb:176:ineach’
/.rvm/gems/ruby-1.8.7-p371/gems/little-plugger-1.1.3/lib/little-plugger.rb:176:in
initialize_plugins' /.rvm/gems/ruby-1.8.7-p371/gems/bones-3.8.0/lib/bones.rb:114:inBones’
/.rvm/gems/ruby-1.8.7-p371/gems/ci_primordial-1.3.49/lib/ci/primordial/tasks/common.rb:76:in
`ci_gem’
/ci/gems/ci_sentiment/Rakefile:5
/.rvm/gems/ruby-1.8.7-p371/bin/ruby_noexec_wrapper:14
(See full trace by running task with --trace)

Here are the list of Gems installed…

[localhost]$ bundle list
Gems included by the bundle:

  • activerecord (2.3.11)
  • activesupport (2.3.11)
  • addressable (2.2.8)
  • arrayfields (4.7.4)
  • bones (3.8.0)
  • bones-rcov (1.0.1)
  • bones-rspec (2.0.1)
  • bundler (1.2.2)
  • chronic (0.6.7)
  • composite_primary_keys (2.2.2)
  • curb (0.7.15)
  • dalli (2.0.5)
  • diff-lcs (1.1.3)
  • expiration-date (1.1.0)
  • fastercsv (1.5.4)
  • fattr (2.2.1)
  • hpricot (0.8.6)
  • htmlentities (4.2.4)
  • i18n (0.6.1)
  • json (1.7.5)
  • little-plugger (1.1.3)
  • logging (1.6.2)
  • loquacious (1.9.1)
  • mail (2.2.19)
  • main (4.6.0)
  • map (6.2.0)
  • mime-types (1.19)
  • nokogiri (1.5.5)
  • pg (0.11.0)
  • polyglot (0.3.3)
  • rake (10.0.2)
  • rcov (0.9.11)
  • rdoc (3.12)
  • rfeedfinder (0.9.13)
  • rfeedreader (1.0.17)
  • rspec (2.6.0)
  • rspec-core (2.6.4)
  • rspec-expectations (2.6.0)
  • rspec-mocks (2.6.0)
  • sequel (3.27.0)
  • simple_uuid (0.1.2)
  • treetop (1.4.12)
  • tzinfo (0.3.35)