Error installing a multimodule archetype created with mvn archetype:create-from-project

I have a project with the following structure:

project (pom)
project-client (module, jar)
project-ejb (module, jar)
project-web (module, war)
project-ear (module, ear)

Inside the pom the modules reference the parent using:

<relativePath>../project</relativePath>

And the root pom references the modules the same way (using ../).

I can create an archetype using archetype:create-from-project, and everything runs smoothly.

But when I try to install the archetype (mvn install inside the target/generated-sources/archetype dir), I get the error:

    [ERROR] Failed to execute goal org.apache.maven.plugins:maven-archetype-plugin:2.2:integration-test (default-integration-test) on project seguranca-archetype:
    [ERROR] Archetype IT 'basic' failed: org.apache.maven.archetype.exception.ArchetypeGenerationFailure: Error merging velocity templates: Unable to find resource 'archetype-resources/../__rootArtifactId__-client/pom.xml'
    [ERROR] -> [Help 1]
    org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-archetype-plugin:2.2:integration-test (default-integration-test) on project seguranca-archetype: 
    Archetype IT 'basic' failed: org.apache.maven.archetype.exception.ArchetypeGenerationFailure: Error merging velocity templates: Unable to find resource 'archetype-resources/../__rootArtifactId__-client/pom.xml'
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:217)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:319)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:616)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
    Caused by: org.apache.maven.plugin.MojoExecutionException: 
    Archetype IT 'basic' failed: org.apache.maven.archetype.exception.ArchetypeGenerationFailure: Error merging velocity templates: Unable to find resource 'archetype-resources/../__rootArtifactId__-client/pom.xml'
        at org.apache.maven.archetype.mojos.IntegrationTestMojo.execute(IntegrationTestMojo.java:268)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
        ... 19 more

The problem is that the file exists (it's on target/generated-sources/archetype/src/main/resources/__rootArtifactId__client/pom.xml), and I tried to fiddle with the archetype-metadata.xml with no success. Any clues?

Thanks in advance

It looks like the archetype plugin doesn't support flat layout for multi-module projects. If that is your case a workaround is to change to a nested layout. I did it by moving the modules outside the archetype-resources directory into it. Like this:

Before:

pom.xml
src
├── main
│   └── resources
│       ├── archetype-resources
│       │   └── pom.xml
│       ├── META-INF
│       │   └── maven
│       │       └── archetype-metadata.xml
│       ├── __rootArtifactId__.module1
│       │   ├── pom.xml
│       │   └── ...
│       ├── __rootArtifactId__.module2
│       │   ├── pom.xml
│       │   └── ...
│       ├── __rootArtifactId__.module3
│           ├── pom.xml
│           └── ...
│
└── test
    └── resources
        └── projects...

After:

pom.xml
src
├── main
│   └── resources
│       ├── archetype-resources
│       │   ├── pom.xml
│       │   ├── __rootArtifactId__.module1
│       │   │   ├── pom.xml
│       │   │   └── ...
│       │   ├── __rootArtifactId__.module2
│       │   │   ├── pom.xml
│       │   │   └── ...
│       │   └── __rootArtifactId__.module3
│       │       ├── pom.xml
│       │       └── ...
│       └── META-INF
│           └── maven
│               └── archetype-metadata.xml
└── test
    └── resources
        └── projects...

And then you edit any reference to the modules in archetype-metadata.xml, removing the '..' relative path.