Running sidekiq gives "Segmentation fault" error on Ubuntu 14.04 running Rails 3.1

Whenever I try to run sidekiq with this command

$ bundle exec sidekiq

I get this error:

/home/myname/.rvm/gems/ruby-1.9.2-p320@somename/gems/celluloid-0.15.2/lib/celluloid/tasks/task_fiber.rb:9: [BUG] Segmentation fault (core dumped)

I am using:

Rails: 3.1.11

Ruby: 1.9.2p320 (2012-04-20 revision 35421) [x86_64-linux]

Ubuntu: 14.04.2 LTS

Sidekiq: ~> 2.15.2

Any help to resolve the issue will be much appreciated. Thanks.