The resource names in the descriptors generated by ruta-maven-plugin have no name qualification at all when importing resources by name. The package names are ignored.
I've created a new Maven project. Added /src/main/ruta as source folder and put the scripts therein. There's no Java involved. The project was deployed with Maven and referenced by a Java UIMA project. Because a variant of the CPE builder from uimaFIT is used, all imports must be by name (The desciptor file of the UIMA aggregate is temporarily written to the systems temp folder). Resource resolution fails. But adding the name qualifications manually solves the issue, e. g. prepending org.apache.uima.ruta.engine to BasicTypeSystem or the project's package names to the generated resources.