Log warn message if leftover shard is detected

core/src/main/java/org/elasticsearch/index/shard/ShardPath.java

@@ -92,6 +92,7 @@ public final class ShardPath {
             ShardStateMetaData load = ShardStateMetaData.FORMAT.loadLatestState(logger, path);
             if (load != null) {
                 if ((load.indexUUID.equals(indexUUID) || IndexMetaData.INDEX_UUID_NA_VALUE.equals(load.indexUUID)) == false) {
+                    logger.warn("{} found shard on path: [{}] with a different index UUID - this shard seems to be leftover from a different index with the same name. Remove the leftover shard in order to reuse the path with the current index", shardId, path);
                     throw new IllegalStateException(shardId + " index UUID in shard state was: " + load.indexUUID + " expected: " + indexUUID + " on shard path: " + path);
                 }
                 if (loadedPath == null) {