While trying to run the core ITs using -DmavenVersion=3.0.1 the build ended up with a resolution failures for a bunch of non-existing artifacts like maven-reporting-api:3.0.1. The problematic artifact versions were coming from a wrong dependency tree like this:
Note that the dependencies of maven-project:2.0.6 use the wrong version.
The problem is due to maven:pom:2.0.6 using the POM property mavenVersion which erroneously gets overridden by my user property.
During dependency resolution, user properties must be treated like system properties and must not override POM properties.