Solr See ${example}/README.txt for how to run the Solr example configuration. ... This task requires that the property 'stub.src.path' be set. It must contain a "path" listing directories containing source files that this task should use when looking for classes that need factories created, the format is platform specific -- typically it is colon seperated in Unix, semi-colon seperated on windows, ie: ant stub-factories -Dstub.src.path="core/src:../lucene/contrib:../lucene/core/src/java:../lucene/analysis" FYI: The file ${stub.list} contains a list of classes that seem to need stub factories. (if java files can be found to use as guides for creating them).