Just the other day I was solving a little problem and I would have liked very much to debug a bit of Java code in a Concordion-based integration test running in my local IntelliJ, but for some reason execution did never stop at my breakpoints.
Main reason for failure? The forking behaviour of the Maven Failsafe plugin!
In the maven-failsafe-plugin version 2.19.1, the default value for the property forkCount is 1, meaning that the plugin will fork a new JVM instance for the execution of tests. A very reasonable setting when executing these tests as part of the build process, but when run from an IDE there is typically no connection to this process and hence debugging is not possible.
Running the maven goal with the property forkCount set to 0 (zero) and the property maven.failsafe.debug set to true did the trick and my problem was quickly solved thanks to the debugging.