Thank you for detecting the bug and the solution proposed.
Changes are already applied on subversion trunk so it will be automatically included in the next release.
Meanwhile, users requiring this patch can get sources from subversion repository as explained in https://sourceforge.net/scm/?type=svn&group_id=193555.
From the output provided I can see that library was succesfully compiled but that there are symbols that cannot be found while linking the examples.
In order to check if the symbols are already present in the library, run the following command from the project home:
nm --dynamic --demangle jaula/.libs/libjaula.so | grep jaulaFlexLexer
If you can see yy_pop_state() and yy_push_state(int...
