Retain the topic.fo file for troubleshooting
Customize your ANT build file to retain topic.fo.
By default, the DITA Open Toolkit discards the topic.fo file after your PDF has been created. Because this file is such a valuable troubleshooting tool, it’s a good idea to retain it along with your PDF.
While topic.fo is always available in the temp folder that is created during each build, it’s not always convenient or possible to retrieve it from there. There used to be a handy parameter, retain.topic.fo, that you could simply add to your ANT build file to copy the topic.fo file to your output folder. That parameter has been deprecated—an unfortunate casualty of the effort to streamline the Open Toolkit and make the behavior of all the plugins ...