Kafka Classpath is empty?

Trying to adjust kafka retention and ran into this issue with the 2.4.2-19.05. None of the Kafka tools will work due to Classpath being empty. Any idea of the right way to fix this?

[root@simplerockbuild kafka]# bin/kafka-topics.sh --describe --zookeeper localhost
Classpath is empty. Please build the project first e.g. by running ‘./gradlew jar -PscalaVersion=2.12.8’

I ran into the same problem. I wrote the question up awhile ago and they told me to use the following to make up for it.
for item in /var/lib/kafka/*.jar; do cp="{cp}:{item}"; done; export CLASSPATH=${cp};

After using this command the tools will work. You also have to drop to root in order to access the files though you probably found that out already.

Perfect thanks! That did the trick.