When errors at end, how to find error

[Harry Putnam]

After a large transfer, when I see an error at the end like:

  sent 2077917 bytes  received 9290799087 bytes  2232523.00 bytes/sec
  total size is 11868499780  speedup is 1.28
  rsync error: some files could not be transferred (code 23) at
               main.c(1385) [generator=2.6.9]
  rsync /www/reader failed ...exiting 2

How can I find these in massive log record?... I mean, what to grep
for?  What would output of such an error (as it occurs) look like?