Fix unit tests. The order of the tests is important since the same groupId/artifactId/version combinations are used in different local repositories in the tests, containing different poms. The DefaultMavenProjectBuilder caches models with g:a:v, so it can serve a model from another local repo. Solved this by changing groupId's in the poms and repositories so they don't conflict.
maven/components/trunk/maven-project/src/test/java/org/apache/maven/project/inheritance/AbstractProjectInheritanceTestCase.java
maven/components/trunk/maven-project/src/test/resources/inheritance-repo/t01/maven/