On 1.9.3 RubyGems deprecates Gem::Specification#loaded? and always returns false.
It says to use Gem::Specification#activated? and it returns true when gemspec is loaded.
rabbit 1.0.0. uses Gem::Specification#loaded? and doesn't work with latest RubyGems.
(so they released rabbit 1.0.1)
This issue was solved with changeset r32652.
okkez, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.
lib/rubygems/specification.rb: Restore behavior of
Gem::Specification#loaded. [Ruby 1.9 - Bug #5032]