Eclipse debug when ant uses temp files
I am bit of a newb with Eclipse and I am looking for guidance of how to adapt an existing batch/ant build system to Eclipse. My build environment takes a set of java and resource files, and uses an ant script to create a temp folder containing all preprocessed files and desired resources. It then proceeds to another ant task that compiles and creates the .jar
I am able to set Eclipse to use the ant script to build everything, in effect replicating a call from the command shell to ant. My greatest problem is debugging. All break points are lost because ant preprocesses the source files to new temp java files and only then it compiles them, in fact removing any debug info. How can I get around this issue and have my cake (temp directory) and eat it too (debug in eclipse)? Currently I am taking the temp files and creating the Eclipse project from there, however any change made to that code has to be merged into the main code base afterward.
Thank you for any hints or suggestions. I have searched far and wide on the net but I didn't find a similar situation.