There is an error in the Ant script build.xml at the root of the OSWorkflow repository :
BUILD FAILED
.../osworkflow/build.xml:91: true is not a legal value for this attribute

In fact, in the task ejbdoclet, the element weblogic needs the attribute createtables with a value of True and not true (stupid bug from xdoclet).

So this patch will correct the problem :
106c106
< <weblogic version="7.0" destdir="${build.java}/META-INF" datasource="defaultDS" createtables="true"/>
---
> <weblogic version="7.0" destdir="${build.java}/META-INF" datasource="defaultDS" createtables="True"/>