Maven Failsafe Plugin Gotcha

I should have known this but it didn't occur to me when integration tests in a Maven project suddently stopped running any test at all. It turned out that the Maven Failsafe Plugin did not have a notion of "compiling test classes" on its own. It is normally not a problem when the plugin is used in a lifecyle. But it falls apart when the failsafe:integration-test goal is executed independently like this:

mvn clean failsafe:integration-test

In this case, the plugin will not run any integration test because not a single class is compiled after clean. The plugin depends on class file naming conventions (such as IT*.class) to run tests. No class file, no test.