When I run ./bin/windup --batchMode --input samples/jee-example-app-1.0.0.ear, I get an error target parameter is required.
When I add the --target parameter with a nonsense value, e.g. --target foobar, all works just fine and I actually get a migration report.
This either means that some default value is chosen, or the program proceeds like if no target was defined. In any case, I just circumvented the fact that target is mandatory.
Either --target shouldn't be required, or its value should be validated.
The same happens in the interactive mode, where I simply enter an invalid value when I'm prompted to select a target: