rsync 3.0.9 incompatible with self? (proto incompat on local->local)

[Linda Walsh]

Familiar?  protocol error on a local file copy?
How can I  have a proto incompat when it it is talking to itself?...

This was on the ERROUT...

rsync: writefd_unbuffered failed to write 4 bytes to socket [sender]: 
Broken pipe (32)
File-list index 531530 not in 531937 - 533437 (finish_hard_link) [generator]
rsync error: protocol incompatibility (code 2) at rsync.c(652) 
[generator=3.0.9]
rsync: connection unexpectedly closed (54286 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at io.c(605) 
[sender=3.0.9]



args used (approx, as they were passed in perl)...

--archive --8-bit-output --human-readable
                --acls --xattrs --hard-links
                --whole-file --one-file-system
            --compare-dest=/home/.
          --exclude={**/.recycle/**,bhome/la**,bhome/athen/**,
                             bhome/root**,bhome/mar** 
CPAN-ishtar-build-cache/**}
            /home/snapdir/old_snapdir/.  /home.diff/