Are you sure this stacktrace is from the ivy-2.2.0-rc1 release? IvyPatternHelper.java:241 (the place where the NPE happens) is an empty line in this release: http://svn.apache.org/viewvc/ant/ivy/core/tags/2.2.0-rc1/src/java/org/apache/ivy/core/IvyPatternHelper.java?revision=959425&view=markup
Maarten
