thanks for the hint. However, are you sure that stderr.txt is not written if the build fails? I assumed that stderr.txt would contain the output to stderr independent of the return status of the java process.

I also think that the Java process does not fail even if the PDE Build fails. That is because the antrunner does not seem to be able to change the return code of the Eclipse instance. So, the Java call only fails if the antrunner can not be invoked, e.g. because of a corrupt Eclipse instance. Therefore we look into stderr later and check for the occurrence of "Build failed".

BTW, the best information for analyzing build errors is usually found in the workspace's log file (${buildDirectory}/workspace/.metadata/.log