NoMethodError in Devise::CasSessionsController#destroy

[rmammina]

Trying to logout user but am getting that error. I'm using rails 4.0. Specifically:
NoMethodError (undefined method `destroy_session' for nil:NilClass)

Which is coming from

app/controllers/devise/cas_sessions_controller.rb:27:in `destroy'

[nbudin]

I believe the line your error is coming from may in fact be this: https://github.com/nbudin/devise_cas_authenticatable/blob/master/lib/devise_cas_authenticatable/single_sign_out.rb#L50

It looks like you're attempting to use the Rails cache as your session store while enabling single sign-out. Is that the case? If so, would it be possible for you to try it using a different single-sign-out-supported session store mechanism (such as the ActiveRecord session store)?