CVS rsync hangs during local copy

[Matt McCutchen]

Dear rsync people (particularly Wayne),

I am finding that the CVS version of rsync hangs during most, but not
all, local copies.  The problem goes away if I pass --protocol=29, so
I'm guessing it is related to the incremental file-list sending.

The hanging seems to be timing-dependent.  Increasing the verbosity
level seems to increase the chance of a hang.  If I run rsync
repeatedly with the same source directory, the chance of a hang seems
to gradually decrease, possibly because the source directory goes into
cache.

I ran the following command line and then killed the rsync processes
when they printed nothing for several seconds:

rm -rf * && strace -ff -o rsync-incremental.strace ~/rsync/rsync/rsync
-a -ivvv --progress ~/rsync/ dest2/ 2>&1 | tee rsync-incremental.log

The resulting rsync-incremental* files are available at:

http://www.kepreon.com/~matt/private/rsync-hanging/

Matt