Maven Version Plugin does not take rules.xml into account

Question

I have included the Maven Versions Plugin into my multi-module project.

I have also declared some rules in rules.xml in a dedicated folder in the root level of my project.

When I run mvn versions:update-properties -pl :foobar -DrulesUri=file:///${project.rootdir}/plugins/maven-versions-plugin/rules.xml, then it appears that the rules are not taken into account.

Here is the rule set:

<?xml version="1.0" encoding="UTF-8"?>
<ruleset xmlns="http://mojo.codehaus.org/versions-maven-plugin/rule/2.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" comparisonMethod="maven" xsi:schemaLocation="http://mojo.codehaus.org/versions-maven-plugin/rule/2.0.0 http://mojo.codehaus.org/versions-maven-plugin/xsd/rule-2.0.0.xsd">
    <ignoreVersions>
        <ignoreVersion type="regex">.*[-_\.](alpha|Alpha|ALPHA|b|beta|Beta|BETA|rc|‌​RC|M|EA)[-_\.]?[0-9]*</ignoreVersion>
    </ignoreVersions>
    <rules>
    </rules>
</ruleset>

I can see that one dependency is, for instance, updated to version 1.0.0-alpha-3 which should be forbidden by the rule.

So my first problem is that I do not know whether the plugin actually considers the rule set. Running the same command with -X did not provide any information on this.

Any ideas?