開発モードではすべて正常に動作しますが、アプリをプロダクション モード (RAILS_ENV=プロダクション スクリプト/サーバー) で起動しようとすると、次のエラーが発生します。
/opt/ruby1.8/lib/ruby/gems/1.8/gems/searchlogic-2.4.19/lib/searchlogic/named_scopes/conditions.rb:81:in `method_missing': protected method `scope' called for #<Class:0x7f41de524410> (NoMethodError)
from /opt/ruby1.8/lib/ruby/gems/1.8/gems/searchlogic-2.4.19/lib/searchlogic/named_scopes/association_conditions.rb:19:in `method_missing'
from /opt/ruby1.8/lib/ruby/gems/1.8/gems/searchlogic-2.4.19/lib/searchlogic/named_scopes/association_ordering.rb:27:in `method_missing'
from /opt/ruby1.8/lib/ruby/gems/1.8/gems/searchlogic-2.4.19/lib/searchlogic/named_scopes/ordering.rb:30:in `method_missing'
from /opt/ruby1.8/lib/ruby/gems/1.8/gems/searchlogic-2.4.19/lib/searchlogic/named_scopes/or_conditions.rb:28:in `method_missing'
from /opt/ruby1.8/lib/ruby/gems/1.8/gems/activerecord-2.3.5/lib/active_record/base.rb:1959:in `method_missing_without_paginate'
from /opt/ruby1.8/lib/ruby/gems/1.8/gems/will_paginate-2.3.12/lib/will_paginate/finder.rb:170:in `method_missing'
from /opt/ruby1.8/lib/ruby/gems/1.8/gems/acts_as_commentable-3.0.0/lib/comment_methods.rb:12:in `included'
from .../app/models/comment.rb:2:in `include'
from .../app/models/comment.rb:2
from /opt/ruby1.8/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
from /opt/ruby1.8/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'...
act_as_commentable 宝石がこれを引き起こしているようです。しかし、開発モードではうまく動作します。