First problem: the module-info.java file is in the wrong directory, so it's completely ignored... It's in integrationtest/jdk/jdk9-modules/src/main/java/ but it should be in integrationtest/jdk/java-modules/src/main/java/.
Second problem: the version of the moditect maven plugin is never set, so Maven (rightfully) issues a warning about that. Let's use dependency management (like everywhere else...).
Third problem: it seems the tests are executed outside of the module path...
If I add this assertion to the test, it will fail:
... proving that the code is in the classpath, not the module path.
This might get a little tricky to fix, because we have a dependency to Lucene, and Lucene has split packages, which prevents it to be in a module (even an automatic module). Since modules can only depend on other modules, not on the classpath, our test module cannot depend on Lucene. Maybe we can convert the tests to use the Elasticsearch backend?