Github user zentol commented on the issue:
https://github.com/apache/flink/pull/6016
hmm, according to the
[javadocs](https://docs.oracle.com/javase/7/docs/api/java/lang/reflect/InvocationTargetException.html)
the wrapped exception is part of the exception chain and accessible via
`getCause()`. Can't try it out mself at the moment though.---
