Cannot compile MapReduceManagerImpl on IBM JDK

Error message:

[ERROR] /home/mgencur/infinispan/infinispan/core/src/main/java/org/infinispan/distexec/mapreduce/MapReduceManagerImpl.java:[176,48] type parameters of <KOut>KOut cannot be determined; no unique maximal instance exists for type variable KOut with upper bounds VIn,java.lang.Object