How To Build Child Modules In Tycho - tycho

Question

I have a multi-module Tycho build with a target definition file. The target definition is defined in it's own project (ID: org.acme.project.target, packaging type: pom) like this:
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>build-helper-maven-plugin</artifactId>
<version>1.3</version>
<executions>
<execution>
<id>attach-artifacts</id>
<phase>package</phase>
<goals>
<goal>attach-artifact</goal>
</goals>
<configuration>
<artifacts>
<artifact>
<file>platform_rcp.target</file>
<type>target</type>
<classifier>platform_rcp</classifier>
</artifact>
</artifacts>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
And the Maven parent refers to this target platform like this:
<plugin>
<groupId>org.eclipse.tycho</groupId>
<artifactId>target-platform-configuration</artifactId>
<configuration>
<resolver>p2</resolver>
<target>
<artifact>
<groupId>${project.groupId}</groupId>
<artifactId>org.acme.project.target</artifactId>
<version>${project.version}</version>
<classifier>platform_rcp</classifier>
</artifact>
</target>
</configuration>
</plugin>
This setup works as long as I build the parent project. When I build one of the child modules, even if this project duplicates the reference to the target platform OR even when I build the parent with mvn install -pl org.acme.project I get the following exception:
[ERROR] Internal error: java.lang.RuntimeException: Could not resolve target platform specification artifact myGroup:org.acme.project.target:target:platform_rcp:2.3.0-SNAPSHOT -> [Help 1]
org.apache.maven.InternalErrorException: Internal error: java.lang.RuntimeException: Could not resolve target platform specification artifact myGroup:org.acme.project.target:target:platform_rcp:2.3.0-SNAPSHOT
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:121)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:862)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:286)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:197)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
Even the Tycho example doesn't work for me, but brings the same error message (Could not resolve target platform specification artifact example.group:mars:target:1.0.0-SNAPSHOT).
I thought this question was similar, but my setup is exactly what is said to work in the answer.
What did I do wrong?
(The actual problem in question is that Eclipse Mars can't run integration tests, so I can only use Tycho to run them, which needs a long time when Tycho builds all modules.)

Answer 1

even when I build the parent with mvn install -pl org.acme.project I get the following exception:
Have you tried prepending the target platform project to the list of -pl arguments: mvn install -pl :mars,org.acme.project
I use this all the time.