Time Machine backup rsync

Issue applies to OSX/MacOS Mojave and Catalina but may be fixed in later versions.

Time Machine backups contain a many hard links that interfere with copying and moving Time Machine backup archives.  Copying the files with Finder causes the hard links to be resolved in a circular fashion causing the copy to run until the target disk is out of space.

Rsync provides an alternative to Finder but may require special configuration.  Attempting to copy Time Machine backup archives using rsync may fail with the error

opendir, operation not permitted.

The error occurs even when root permissions have been acquired with sudo.

The issue is caused by the new application security layer introduced with Mojave.

To enable copying of Time Machine backups using rsync the terminal.app application must be added to the Full Disk Access application permissions list in System Preferences/Security and Privacy\Privacy tab.