port -v selfupdate failed

[werewolflsp@…]

I did a full restore from time machine. At the end of restoration, there was a message telling me that the user ID of macports would be changed from 502 to 503(I'm not sure about the numbers...) But I didn't check if mac port works fine for some time...

% port -v selfupdate                                                       
--->  Updating MacPorts base sources using rsync
USTC open source mirror

@ERROR: chroot failed
rsync error: error starting client-server protocol (code 5) at /SourceCache/rsync/rsync-42/rsync/main.c(1398) [receiver=2.6.9]
Command failed: /usr/bin/rsync -rtzv --delete-after rsync://mirrors.ustc.edu.cn/macports/base/ /opt/local/var/macports/sources/mirrors.ustc.edu.cn/macports/base
Exit code: 5
Error: Error synchronizing MacPorts sources: command execution failed
To report a bug, follow the instructions in the guide:
    http://guide.macports.org/#project.tickets
Error: /opt/local/bin/port: port selfupdate failed: Error synchronizing MacPorts sources: command execution failed