In multi-module project, integration tests are not run if no classes present in src/main/java of integration tests module

See attached zip with project as a small reproduction of our problem (only 4 modules, for our enterprise application, we have 87).

Several modules with own unit tests and one integration test module without any class in src/main/java.

Since we don't want to have all the standard unit tests run twice, we do sonar in two phases (and it is the recommended way of doing according to Sonar documentation http://docs.codehaus.org/display/SONAR/Collect+data):

• mvn clean install -DskipTests
• mvn --fail-at-end -Dmaven.test.failure.ignore sonar:sonar

In this case, the integration tests are not run.

If we do it in one pass:

• mvn --fail-at-end -Dmaven.test.failure.ignore clean install sonar:sonar
  It works and we have all the tests as they are run by the install first, but most of the tests are then run again by sonar (for coverage). In our case, this means having 1h more of build (several thousands tests), which we cannot afford to.

So it would be great to have all the tests (unit and integration) run by sonar even if there are no classes to instrument for coverage in a module.