When using pty=true, removing files using sudo may request confirmation,
which will hang the connection.
Similarly, sometimes assumptions about file existence may be wrong and
in those cases it seems better to continue on as long as the file does
not exist, so -f makes sense there, too.
Run remote rsync as root to guarantee that rsync can write to guestpath.
This obviates the need to chown the guestpath to the SSH user prior to
sync.
This brings a substantial speedup (2x on a moderately-sized shared
folder) and properly triggers filesystem notifications on only the files
changed by a given sync.
Leo Simons
Kalman Hazins
Teemu Matilainen
Mitchell Hashimoto
Nikhil Benesch
Stoned Elipot