In https://github.com/thorntail/thorntail/pull/1141, we renamed all the configuration properties from swarm to thorntail. Compatibility is provided for the YAML files, but apparently, not for system properties. I voiced that concern in the PR, but got no response.
In an unrelated work, I just ran the Thorntail standalone test suite against current master (2.3.0.Final-SNAPSHOT), and the web hollow JAR test is failing. This is because the test uses swarm.classpath to put the JDBC driver on classpath. This system property is no longer recognized. If I change the Java invocation to use thorntail.classpath, it works fine. This confirms my concern from the previously mentioned PR. I strongly believe we must not break compatibility like this, especially in a micro release!