The first time you try Arquillian, you may find that assertions that use the Java assert keyword are not working. Keep in mind that the test is not executing the same JVM as the test runner.
In order for the Java keyword "assert" to work you have to enable assertions (using the -ea flag) in the JVM that is running the container. You may want to consider specifying the package names of your test classes to avoid assertions to be enabled throughout the container's source code.
If you are using JBoss AS, the quickest way to setup debug mode is to add the following line to the end of $JBOSS_AS_HOME/bin/run.conf (Unix/Linux):
or before the line :JAVA_OPTS_SET in $JBOSS_AS_HOME/bin/run.conf.bat (Windows)
Keep in mind your container will always run with assertions enabled after making this change. You might want to consider putting some logic in the run.conf* file.
As an alternative, we recommend using the 'Assert' object that comes with your test framework instead to avoid the whole issue. Also keep in mind that if you use System.out.println statements, the output is going to show up in the log file of the container rather than in the test output.