generated folder is empty when using absolut paths

When I use relative paths from my Java project like this: 

```
integratej2objc integrate_source -p ../Test111 -x Test111.xcodeproj -s ../TestJ2Objc/build/j2objc -g generated_source -t Test111
```

everything works fine. But when I turn these paths into absolute paths the `generated_source` folder is created but it does not contain any files.
