rsync error code 12 at phase "unknown"

[Edward King]

Any suggestions on tracking this problem down?  We've had it happen on a 
few machines -- some through VPN's, one from a Mac OS X to a Linux 
machine on the local network.

Some machines never have this problem.  We think it's a hiccup in the 
network connection -- but it's very minor.  We've setup pings and 
tracked the data sent through the interface and have never seen it drop 
below 300 bytes / 5 second slice (so we know the connection isn't 
crashing down on us -- besides, the retry should catch it.)

I have checked the usual culprits and think my next step is to wade into 
the code (disk space good, timeouts virtually nonexistent, cpu load low, 
lots of free memory, etc.)

The phase shows unknown, and the call in io.c is simply a write function 
-- any suggestions on back tracking to find what is calling the write?  
Maybe we can restart the phase that's failing (kind of like transaction 
framing for sql -- perform a commit/rollback operation.)  It works 
great, just seems vulnerable to a lost packet somewhere.

Log from "rsync --partial -v -a -z --delete --backup --suffix='.backup' 
--bwlimit=15 /. 10.1.1.61::/save/":

building file list ... done
etc/cups/certs/0
etc/mail/statistics
etc/mail/logs/092603
rsync: writefd_unbuffered failed to write 16385 bytes: phase "unknown": 
Connection timed out
rsync error: error in rsync protocol data stream (code 12) at io.c(515)