./test/hbal $BACKEND_EXCL --exclude-instances no-such-instance
>>>2 /Unknown instance/
>>>= !0

./test/hbal $BACKEND_EXCL --select-instances no-such-instances
>>>2 /Unknown instance/
>>>= !0

./test/hbal $BACKEND_EXCL --exclude-instances new-0 --select-instances new-1
>>>= 0