java.lang.ClassCastException: jline.console.history.MemoryHistory$EntryImpl cannot be cast to java.lang.String

irb(main):001:0> RUBY_DESCRIPTION
=> "jruby 1.7.0.dev (ruby-1.9.3-p139) (2012-04-15 f187111) (Java HotSpot(TM) 64-Bit Server VM 1.6.0_31) [darwin-x86_64-java]"
irb(main):002:0> exit
Readline.java:382:in `s_hist_to_a': java.lang.ClassCastException: jline.console.history.MemoryHistory$EntryImpl cannot be cast to java.lang.String
	from Readline$HistoryMethods$INVOKER$s$0$0$s_hist_to_a.gen:-1:in `call'
	from CachingCallSite.java:292:in `cacheAndCall'
	from CachingCallSite.java:135:in `call'
	from CallNoArgNode.java:63:in `interpret'
	from DAsgnNode.java:110:in `interpret'
	from NewlineNode.java:104:in `interpret'
	from BlockNode.java:71:in `interpret'
	from ASTInterpreter.java:112:in `INTERPRET_BLOCK'
	from Interpreted19Block.java:209:in `evalBlockBody'
	from Interpreted19Block.java:160:in `yield'
	from Block.java:130:in `yield'
	from RubyIO.java:1105:in `open'
	from RubyKernel.java:285:in `open'
	from RubyKernel.java:295:in `open19'
	from RubyKernel$INVOKER$s$0$2$open19.gen:-1:in `call'
	from DynamicMethod.java:224:in `call'
	from CachingCallSite.java:342:in `cacheAndCall'
	from CachingCallSite.java:212:in `callBlock'
	from CachingCallSite.java:221:in `callIter'
	from FCallTwoArgBlockNode.java:34:in `interpret'
	from NewlineNode.java:104:in `interpret'
	from BlockNode.java:71:in `interpret'
	from IfNode.java:116:in `interpret'
	from NewlineNode.java:104:in `interpret'
	from ASTInterpreter.java:75:in `INTERPRET_METHOD'
	from InterpretedMethod.java:147:in `call'
	from DefaultMethod.java:183:in `call'
	from CachingCallSite.java:292:in `cacheAndCall'
	from CachingCallSite.java:135:in `call'
	from CallNoArgNode.java:63:in `interpret'
	from NewlineNode.java:104:in `interpret'
	from ASTInterpreter.java:112:in `INTERPRET_BLOCK'
	from Interpreted19Block.java:209:in `evalBlockBody'
	from Interpreted19Block.java:197:in `yield'
	from Interpreted19Block.java:128:in `call'
	from Block.java:89:in `call'
	from RubyProc.java:269:in `call'
	from RubyProc.java:257:in `call19'
	from RubyProc$INVOKER$i$0$0$call19.gen:-1:in `call'
	from DynamicMethod.java:208:in `call'
	from DynamicMethod.java:204:in `call'
	from CachingCallSite.java:292:in `cacheAndCall'
	from CachingCallSite.java:135:in `call'
	from CallNoArgNode.java:63:in `interpret'
	from NewlineNode.java:104:in `interpret'
	from ASTInterpreter.java:112:in `INTERPRET_BLOCK'
	from Interpreted19Block.java:209:in `evalBlockBody'
	from Interpreted19Block.java:160:in `yield'
	from Block.java:130:in `yield'
	from RubyArray.java:1604:in `eachCommon'
	from RubyArray.java:1611:in `each'
	from RubyArray$INVOKER$i$0$0$each.gen:-1:in `call'
	from CachingCallSite.java:302:in `cacheAndCall'
	from CachingCallSite.java:144:in `callBlock'
	from CachingCallSite.java:153:in `callIter'
	from CallNoArgBlockNode.java:64:in `interpret'
	from NewlineNode.java:104:in `interpret'
	from ASTInterpreter.java:75:in `INTERPRET_METHOD'
	from InterpretedMethod.java:147:in `call'
	from DefaultMethod.java:183:in `call'
	from CachingCallSite.java:292:in `cacheAndCall'
	from CachingCallSite.java:135:in `call'
	from VCallNode.java:86:in `interpret'
	from NewlineNode.java:104:in `interpret'
	from EnsureNode.java:98:in `interpret'
	from BeginNode.java:83:in `interpret'
	from NewlineNode.java:104:in `interpret'
	from BlockNode.java:71:in `interpret'
	from ASTInterpreter.java:75:in `INTERPRET_METHOD'
	from InterpretedMethod.java:190:in `call'
	from DefaultMethod.java:199:in `call'
	from CachingCallSite.java:312:in `cacheAndCall'
	from CachingCallSite.java:169:in `call'
	from /Users/asari/Development/src/jruby/bin/jirb:13:in `__file__'
	from /Users/asari/Development/src/jruby/bin/jirb:-1:in `load'
	from Ruby.java:776:in `runScript'
	from Ruby.java:769:in `runScript'
	from Ruby.java:648:in `runNormally'
	from Ruby.java:497:in `runFromMain'
	from Main.java:375:in `doRunFromMain'
	from Main.java:264:in `internalRun'
	from Main.java:230:in `run'
	from Main.java:214:in `run'
	from Main.java:194:in `main'