Create a new Java Modular Project in Ant and run it, you will see it fails.

Steps to simulate :

1.Ctrl+shift+n -> Dialogue box will be opened -> from Categories select Java with Ant > from Projects select Java Modular Project -> click Next -> enter project name in Project Name box -> click on Finish.

     After performing above steps Java Modular Project will be created.

2.Right click on created project -> New -> Module -> Dialogue box will be opened -> enter module name in Module Name field -> click on Finish.

    After performing above steps Module will be created.

3.Create classes inside created Module and run it, you will see project is failing.