executeworkflow doesn't produce any output

That's normally a good sign! Stack traces should make you slightly more worried, although this could also be normal.

By default, when using executeworkflow, the output of the workflow will be written to a directory named after the workflow file. So if you executed:

executeworkflow.sh my_workflow.xml

you should find a directory my_workflow.xml_output, containing at least progressReport.xml, and a directory structure for the workflow output.

Note that you can modify the output options, run with option -help for more information.