Due to a bug in the cwltool (or maybe it is intentional) individual cwl files are missing from the PROV/workflow/ location and only the PROV/workflow/packed.cwl is available. This only happens when you start the workflow with a cwl:tool: argument in the input yaml file.
In theory the packed.cwl should be sufficient or not? Not sure if this is an issue in runcrate but I thought I would let you know.
http://download.systemsbiology.nl/unlock/cwl/issues/PROV_No_CWL.zip (Removed the .DS_Store files).