I’m curious to know what the real problem with tying a module’s version to the parent version is, if any? Or is this a case of a general warning when any expression, regardless of whether it’s project.parent.version, is used for the version element.
Well, that would be easy to test. Because I was curious, I just did it for you using the following pom:
<project>
<modelVersion>4.0.0</modelVersion>
<parent>
<artifactId>parent</artifactId>
<groupId>com.mycompany</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<groupId>com.mycompany</groupId>
<artifactId>module</artifactId>
<version>${myversion}</version>
<name>module</name>
<url>http://maven.apache.org</url>
<properties>
<myversion>1.0-SNAPSHOT</myversion>
</properties>
...
</project>
And maven is indeed complaining:
[WARNING] 'version' contains an expression but should be a constant. @ com.mycompany:module:${myversion}, /home/pascal/Projects/maven-maven3-testcase/module/pom.xml
To be honest, I think that maven is right here, it doesn’t make much sense to use a property for the <version>
element (at least not for project.version) and it’s nice to have maven complaining about it.
And if you want to use the parent pom version in sub-modules, just remove the <version>
tag from the child poms, they will inherit the version from the parent. What you are currently doing is unnecessary.