build project
  
and see Forrestdoc generate documentation for itself in build/project

  build ws
  
and see Forrestdoc generate documentation for the workspace it's put in
(workspace/xml-forrest/scratchpad/forrestdoc -> generate for all projects in workspace/)

to set a workspace dir manually:

 -Dws.dir=
 
to set a project dir manually:
 
 -Dproject.dir=