Maven: properties not being substituted - maven-2

Question

I'm using a maven plugin for install4j in my project, located here. That plugin lets you pass variables to install4j using the <compilerVariables> section. Here's the relevant section of my pom:
<plugin>
<groupId>com.google.code.maven-install4j</groupId>
<artifactId>maven-install4j-plugin</artifactId>
<version>0.1.1</version>
<configuration>
<executable>${devenv.install4jc}</executable>
<configFile>${basedir}/newinstaller/ehd.install4j</configFile>
<releaseId>${project.version}</releaseId>
<attach>false</attach>
<skipOnMissingExecutable>false</skipOnMissingExecutable>
<compilerVariables>
<property>
<name>m2_home</name>
<value>${settings.localRepository}</value>
</property>
</compilerVariables>
</configuration>
</plugin>
The problem is that ${settings.localRepository} is not being substituted with the actual directory when I run the plugin. Here's the command line script that install4j is generating:
[INFO] Running the following command for install4j compile: /bin/sh -c /home/zach/install4j/bin/install4jc --release=9.1-SNAPSHOT --destination="/home/zach/projects/java/ehdtrunk/target/install4j" -D m2_home=${settings.localRepository} /home/zach/projects/java/ehdtrunk/newinstaller/ehd.install4j
Is this the fault of the plugin? If so, what needs to change to allow the substitution to happen?

Answer 1

The following POM just works for me (with Maven 2.2.1):
<project>
<modelVersion>4.0.0</modelVersion>
<groupId>com.stackoverflow</groupId>
<artifactId>Q2828732</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
...
</dependencies>
<build>
<plugins>
<plugin>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<execution>
<phase>validate</phase>
<configuration>
<tasks>
<echo>${settings.localRepository}</echo>
</tasks>
</configuration>
<goals>
<goal>run</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
And running mvn process-ressources produces the following output:
$ mvn validate
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Q2828732
[INFO] task-segment: [validate]
[INFO] ------------------------------------------------------------------------
[INFO] [antrun:run {execution: default}]
[INFO] Executing tasks
[echo] /home/pascal/.m2/repository
[INFO] Executed tasks
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2 seconds
[INFO] Finished at: Thu May 13 19:28:38 CEST 2010
[INFO] Final Memory: 3M/54M
[INFO] ------------------------------------------------------------------------
Does the above work for you? Are you using M2Eclipse? Could it be related to MNGECLIPSE-299?

Answer 2

The plugin in question accepts a parameter which is a Properties instance. For whatever reason, expressions used to configure Properties instances are not automatically evaluated. I had to change the plugin to use a org.apache.maven.plugin.PluginParameterExpressionEvaluator to evaluate ${settings.localRepository}.