rsync on macOS Catalina : filename overflows max-path len by 2
Rsync has internal buffers to hold the names of files. These are hardcoded to have a value MAXPATHLEN which is defined to be an OS dependant value or  1024 in the code from https://github.com/WayneD/rsync/blob/d2a97a7ab492e0d0548708251309e077e6aa8c8b/rsync.h
So you path names are too long for either macos or rsync