in 2.1.6 Mapper.getQuery(Object) returned CQL that was not aliased. in 2.1.7 CQL contains aliases all for columns with the convention "as COL[COL_COUNT]". This CQL can't be passed to Mapper.map(Object). By reading your source I found I could change my code to call to Mapper.mapAliased(Object) instead, but now I have to know if the CQL being passed in is aliased or not (sometimes it is, sometimes it isn't), so for one, code that was working before now does not run, and the only change was the driver version (you broke backwards compatibility with existing code), and two, I know have to know about the CQL coming in at the level my code calls the mapper. This makes for unpleasant code. changing Mapper.map(Object) to detect aliases and handle it internally would have maintained backwards compatibility and been cleaner from a client perspective.
Mapper.map(ResultSet) can now handle both aliased (mapper-generated) and non-aliased (from user queries) result sets.
mapAliased has been deprecated (the current implementation calls map), it will be removed in a future version.