Maven prerequisite is required in the build

Considering the Enforcer Plugin's FAQ, I'm not sure that <prerequisites> is the best way to go. Maybe use the plugin's requireMavenVersion instead. This would IMHO more clearly express that it's a build requirement, not a runtime requirement.

I'm curious what makes qdox require at least maven-2.0.10. I don't know if it's a problem to require one of the most recent maven installations. Maybe supporting 2.0.8 would be nice.

With Maven 2.0.9 I got:

[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] 'copy-resources' was specified in an execution, but not found in the plugin

But that does not really require a newer Maven version, merely the version for the maven-resources-plugin needs to be locked down to its latest version. BTW, other build plugins are also missing versions: maven-clean-plugin, maven-surefire-plugin, maven-install-plugin, maven-deploy-plugin. Relying on the defaults provided by Maven seems to be the cause why the build result depends on the Maven version.

seems like the maven-resources-plugin was the only one without a version. Added 2.3 to this plugin.
I've tested it with maven 2.0.9 and everything looks fine. This should be good enough.

seems like the maven-resources-plugin was the only one without a version.

No, the QDox POM does not specify versions for maven-clean-plugin, maven-surefire-plugin, maven-install-plugin and maven-deploy-plugin. So, for Maven 2.0.8-, these plugins get resolved to their latest release, while in Maven 2.0.9+ you get whatever has been set in the super POM. In both cases, your build depends on external settings and a different Maven version could produce different outputs from the same POM. Locking down plugin versions is not limited to just the plugins explicitly declared in the POM, it should be done for each plugin your build uses, including the implicitly used plugins for the default lifecycle bindings.

All default-lifecycle and clean-lifecycle plugins versions are now locked. QDox works with maven 2.0.8 and above.