Warning if plugin is executed in parallel

[renedewaele]

When version 2.7 of this plugin is executed in a parallel maven build (maven version 3.5.4) I'm getting the following warning:

* Your build is requesting parallel execution, but project      *
* contains the following plugin(s) that have goals not marked   *
* as @threadSafe to support parallel building.                  *
* While this /may/ work fine, please look for plugin updates    *
* and/or request plugins be made thread-safe.                   *
* If reporting an issue, report it against the plugin in        *
* question, not against maven-core                              *
*****************************************************************
The following plugins are not marked @threadSafe in Flux Capacitor:
org.codehaus.mojo:versions-maven-plugin:2.7
Enable debug to see more precisely which goals are not marked @threadSafe.
*****************************************************************

My plugin configuration is as follows:

<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>versions-maven-plugin</artifactId>
    <version>2.7</version>
    <configuration>
        <rulesUri>file:///${user.dir}/versions-plugin-rules.xml</rulesUri>
    </configuration>
    <executions>
        <execution>
            <phase>compile</phase>
            <goals>
                <goal>display-dependency-updates</goal>
                <goal>display-plugin-updates</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Related issue: #293. Is this not fixed yet or am I doing anything wrong?

[famod]

12c9cb9 did not add threadSafe = true to DisplayDependencyUpdatesMojo (by mistake?).

https://github.com/mojohaus/versions-maven-plugin/blob/master/src/main/java/org/codehaus/mojo/versions/DisplayDependencyUpdatesMojo.java#L56
vs.
https://github.com/mojohaus/versions-maven-plugin/blob/master/src/main/java/org/codehaus/mojo/versions/DisplayPluginUpdatesMojo.java#L101