<configuration>

  <evaluator name="DISPLAY_EX_EVAL">
    <expression>throwable != null &amp;&amp; throwable instanceof chapters.layouts.TestException</expression>
  </evaluator>

  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
      <pattern>%msg%n%xEx{full, DISPLAY_EX_EVAL}</pattern>
    </encoder>
  </appender>

  <root level="DEBUG">
    <appender-ref ref="STDOUT" />
  </root>
</configuration>