asset-pipeline - JRubyでejsアセットをプリコンパイルするときにTrueClassを複製できません

Question

rake Assets：precompileをJRubyで実行すると、次のバックトレースが発生します。

can't dup TrueClass
  (in C:/tripwire/app/assets/templates/alert_histories/index.jst.ejs.slim)
org/jruby/RubyKernel.java:1908:in `dup'
org/jruby/RubyArray.java:1613:in `each'
org/jruby/RubyArray.java:1613:in `each'
org/jruby/RubyArray.java:1613:in `each'
org/jruby/RubyArray.java:1613:in `each'
org/jruby/RubyProc.java:249:in `call'
org/jruby/RubyArray.java:1613:in `each'
org/jruby/RubyProc.java:249:in `call'
org/jruby/RubyArray.java:1613:in `each'
org/jruby/RubyArray.java:1613:in `each'
org/jruby/RubyKernel.java:1046:in `load'
Tasks: TOP => assets:precompile:primary
(See full trace by running task with --trace)
rake aborted!
Command failed with status (1): [c:/jruby-1.7.2/bin/jruby.exe c:/jruby-1.7....]
org/jruby/RubyProc.java:249:in `call'
org/jruby/RubyProc.java:249:in `call'
org/jruby/RubyArray.java:1613:in `each'
org/jruby/RubyArray.java:1613:in `each'
org/jruby/RubyKernel.java:1046:in `load'
Tasks: TOP => assets:precompile
(See full trace by running task with --trace)

他の誰かがこれに遭遇しましたか？アドバイスをいただければ幸いです

関連するgemのバージョンは次のとおりです。

 ejs (1.1.1)
 rails (3.2.8)
 rake (10.0.3)
 jruby 1.7.2 (Ruby 1.9)