Why does an attached CRaSH shell throw a NullPointerException when issuing commands?

Question

After attaching a CRaSH shell to a running java process using

> crash.bat pid

starting CRaSH with a JDK, calling the help command returns an error

% help

help: exception: NullPointerException

This means that the commands are not compiled. Why does this happen despite starting CRaSH shell with a JDK?

Answer 1

As correctly noted, the CRaSH shell must run with a JDK as it needs the Java compiler.

The same is required when attaching a CRaSH shell . From the CRaSH reference documentation : "CRaSH will hook into the targetted JVM instead of the JVM started by CRaSH"

TL;DR

The process the CRaSH shell is attached to must run using a JDK!