You probably noticed that BackupPC fails to backup your cPanel host over rsync with the following error:
Got fatal error during xfer (fileListReceive failed)
Nothing else. Nada.
If you increase the ssh verbosity, you will see that there is an error stdin: is not a tty.
It turns out that cPanel adds mesg y to your .bashrc and /etc/bashrc, which somehow messes up the remote rsync data channel over ssh.
To overcome this issue, add on top of your .bashrc and /etc/bashrc on cPanel host:
if [ $(expr index "$-" i) -eq 0 ]; then