None have quote around when script option is use and port is not in used

When you use the recipe without port opition and with script option to true, rsync does'nt work. Indeed, it give a string 'None' on argument port. And when rsync method try to launch command, it try with a port because of

    if port:

on __init__.py file

For example, if add this parts on my buildout

    [rsync-datafs]
    recipe = collective.recipe.rsync
    source = user@hostname:path/to/data/fs
    target = ${buildout:directory}/var/filestorage/Data.fs
    script = true

will generate a command like this

    collective.recipe.rsync.__init__.rsync(
        source='user@hostname:path/to/data/fs', 
        target='tagret/path', 
        port='None'))

and it shoud be

    collective.recipe.rsync.__init__.rsync(
        source='user@hostname:path/to/data/fs', 
        target='tagret/path', 
        port=None))

There, None is no more a string