I just upgrade from compass 2.1.4 to 2.2.0 and found out that batch indexing wouldn't work anymore. I was using PaginationHibernateIndexEntitiesIndexer and SameThreadParallelIndexExecutor to batch index using a HibernateGpsDevice. However, the batch indexing failed with the attached log.
After changing back to ConcurrentParallelIndexExecutor, the index finished without problems. I wasn't able to find the exact reason, but it seemed that the newly build index was already moved from gpsindex to index before the java.io.FileNotFoundException: /tmp/app/index/gpsindex/artist/segments_2 (No such file or directory) was thrown.