Behavior when multiple tiles define the same profile differently is unclear

[udalrich]

The documentation does not say what happens when a profile is defined with the same id but different implementations in different tiles.

I have the following profile in my inheritance-based pom:

    <profile>
        <id>attachDebugger</id>
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <configuration>
                        <!-- Wait for debugger to attach to port 5005 -->
                        <debugForkedProcess>true</debugForkedProcess>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-failsafe-plugin</artifactId>
                    <configuration>
                        <!-- Wait for debugger to attach to port 5005 -->
                        <debugForkedProcess>true</debugForkedProcess>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </profile>

Logically, when converting to tiles, I would expect to define a tile to run surefire and a separate tile to run failsafe. In each tile, I would like to define a profile with id attachDebugger that defines the appropriate plugin with the given configuration. It is unclear if I do this if I will get build errors, the profiles will be merged or if one profile will win and the other will be (silently?) ignored.

[rvowles]

We use the code in Maven itself to merge poms together, it is the same code used when merging parents. That said, I have spoken with someone else who had some difficulty trying to figure out what was going on with his profiles - but that was more about them existing at all rather than them merging.

If you put stuff in a tile and then do a mvn help:effective-pom - it should tell you what you get.