diff -ru jruby-0.9.8/build.xml jruby-0.9.8-patched/build.xml
--- jruby-0.9.8/build.xml	2007-03-05 18:44:49.000000000 -0500
+++ jruby-0.9.8-patched/build.xml	2007-03-11 15:54:01.000000000 -0400
@@ -137,6 +137,7 @@
       <classpath refid="build.classpath"/>
       <classpath path="${jruby.classes.dir}"/>
       <sysproperty key="jruby.dump_invocations" value="${jruby.classes.dir}"/>
+      <jvmarg value="-Djruby.home=${basedir}"/>
       <arg value="-rjava"/>
       <arg value="${build.dir}/__empty.rb"/>
     </java>