To debug the the lifecycle phases of a Tobago application you can configure the DebugPhaseListener.

Add the following into your faces-config.xml 

  <lifecycle>
    <phase-listener>
      org.apache.myfaces.tobago.util.DebugPhaseListener
    </phase-listener>
  </lifecycle>

And configure your logging system to info, debug or trace for this class.

e.g. in log4j.xml: 

  <category name="org.apache.myfaces.tobago.util.DebugPhaseListener">
    <priority value="debug" />
  </category>