Affects PMD Version:
6.28.0

Description:
Command line interface:

There are a couple of problems with the error code returned
currently. If failOnViolations is set and PMDException occurs, the error
code returned is 0, not 1. That's not expected.
If violations are present as well, the error code returned is 4, not 1.
Is this the norm or expected behaviour? It must be 1 while not failing to process violations.

When both occur, the more severe error code must be returned; in this case, 1.

Running PMD through:
CLI

PS: It's been a while since I've used the CLI. And it has slipped my mind as how to simulate a PMDException while executing it.

Referred from here.