Reproduction recipe for https://issues.apache.org/jira/browse/LOG4J2-2196

log4j2-2196.xml

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn">
  <Appenders>
    <Console name="Console" target="SYSTEM_OUT" direct="true">
      <PatternLayout pattern="%d{DEFAULT} | %msg%varsNotEmpty{ | EXCEPTION: %throwable}%n"/>
    </Console>
  </Appenders>
  <Loggers>
    <Root level="debug">
      <AppenderRef ref="Console"/>
    </Root>
  </Loggers>
</Configuration>

stdout.log

2018-01-18 18:58:05,157 | Start
2018-01-18 18:58:05,160 | This is a test. | EXCEPTION: java.lang.Exception: Test exception!
	at TestLogging.main(TestLogging.java:9)

java.lang.Exception: Test exception!
	at TestLogging.main(TestLogging.java:9) [classes/:?]
2018-01-18 18:58:05,164 | End

TestLogging.java

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

public class TestLogging {
  private static final Logger logger = LogManager.getLogger("HelloWorld");

  public static void main(String[] args) {
    logger.info("Start");
    logger.info("This is a test.", new Exception("Test exception!"));
    logger.info("End");
  }
}