I get the following exception:

2006-03-21 16:06:54,053 [Thread-1366] INFO - Checking necessary condition of step "copyArtifacts".
2006-03-21 16:06:54,053 [Thread-1366] INFO - Condition satisfied, running step "copyArtifacts".
2006-03-21 16:06:54,053 [Thread-1366] ERROR - Build failed.
java.lang.IllegalArgumentException: Illegal group reference
at java.util.regex.Matcher.appendReplacement(Matcher.java:706)
at java.util.regex.Matcher.replaceFirst(Matcher.java:848)
at com.pmease.quickbuild.model.Configuration.evaluateStringExpression(Configuration.java:859)
at com.pmease.quickbuild.web.editable.Editable.resolveOgnlExpressions(Editable.java:116)
at com.pmease.quickbuild.builder.Builder.resolveOgnlExpressions(Builder.java:64)
at com.pmease.quickbuild.builder.Builder.execute(Builder.java:74)
at com.pmease.quickbuild.step.BuildStep.run(BuildStep.java:60)
at com.pmease.quickbuild.step.Step.trigger(Step.java:161)
at com.pmease.quickbuild.step.SerialStep.triggerMembers(SerialStep.java:35)
at com.pmease.quickbuild.step.CompositeStep.run(CompositeStep.java:129)
at com.pmease.quickbuild.step.Step.trigger(Step.java:161)
at com.pmease.quickbuild.model.Configuration.performBuild(Configuration.java:1251)
at com.pmease.quickbuild.model.Configuration.trigger(Configuration.java:980)
at com.pmease.quickbuild.triggeringinstance.ManualTriggeringInstance.execute(ManualTriggeringInstance.java:41)
at com.pmease.quickbuild.model.Queue$BuildRunner.run(Queue.java:221)
at java.lang.Thread.run(Thread.java:595)

This step runs a ant builder (inherited from the root configuration)
Details of this builder are: ant 1.5.4
Build properties
 srcDir=${var["copySrc"]}
 filesetInclude=${var["copyInclude"]}
 filesetExclude=${var["copyExclude"]}
 destDir=${build.artifactsDir}
Build targets "copy"

The rest is default

Ant script is:

<project name="copy-artifacts" default="copy">
        <target name="copy">
                <echo message="srcDir=${srcDir}"/>
                <echo message="destDir=${destDir}"/>
                <echo message="filesetInclude=${filesetInclude}"/>
                <echo message="filesetExclude=${filesetExclude}"/>
                <copy todir="${destDir}">
                        <fileset dir="${srcDir}">
                                <include name="${filesetInclude}"/>
                                <exclude name="${filesetExclude}"/>
                        </fileset>
                </copy>
        </target>
</project>

In the child configuration, I add this to basic settings variables
copySrc=${checkoutsDir}/ui/target
copyInclude=*.[wj]ar

It's probably something I did wrong, but it's hard to figure out which part...