The default version 2.6.9 of rsync in macOS was released in nov 2006. And there has been several fixes and releases since then. The news about the current release of rsync is here. Due to new features in rsync and dependency to shared libraries it is not possible to bundle the latest version together with RsyncOSX.
It is adviced to install rsync as part of Homebrew. In RsyncOSX select user configuration and set path for optional version of rsync. Install homebrew and install the latest version of rsync as part of homebrew. Execute the command
brew install rsync to install the latest version of rsync.
RsyncOSX supports snapshots of files. Due to a bug in version 2.6.9 in rsync, the snapshot feature of RsyncOSX require to install rsync version 3.1.3 or higer.
Compile the latest version
The source code for the latest version of rsync can be downloaded from rsync.samba.org. There are some new features within the latest version and it require some additional libraries. I recommend to install the latest version as part of Homebrew. If you have installed Xcode command line tools and the required libraries you can also compile your own version of rsync. The following dynamic libraries is required:
Before a compile set the environment variables to let the
configure script to find the libraries. The libraries is also installed as part of Homebrev.
Then execute the
configure script to produce the makefile. I also instructs configure to install rsync in
LastMod 2020-12-13 (5f7d28a)