java.lang.ClassFormatError for JRuby 1.60RC3 under IBM Java


I am having the following error when running the latest jruby under
IBM JDK. any clue on the issue?

jruby -S rake -T defineClass': java.lang.ClassFormatError: JVMCFRE068 cl ass name is invalid; class=rubyjit $initialize_9FFD7936C93B2FA4E78CC51FF56BE551BF 6DD8A6#block_0$RUBY$__file__, offset=0 from’

jruby -v
jruby 1.6.0.RC3 (ruby 1.8.7 patchlevel 330) (2011-03-08 bb55fc0) (IBM
J9 VM 1.6.

  1. [Windows XP-x86-java]

java -version
java version “1.6.0”
Java™ SE Runtime Environment (build
pwi3260sr8fp1ifix-20100903_02(SR8 FP1+IZ83654))
IBM J9 VM (build 2.4, JRE 1.6.0 IBM J9 2.4 Windows XP x86-32
jvmwi3260sr8-20100401_55940 (JIT enabled, AOT enabled)
J9VM - 20100401_055940
JIT - r9_20100401_15339
GC - 20100308_AA)
JCL - 20100903_02