port selfupdate failure on macOS Sierra

[jpwhiting (Jeremy Whiting)]

I am recently getting this when I do sudo port -d selfupdate. The guys in #macports suggested it's an update on the server gone wrong. so I'm creating this ticket.

DEBUG: MacPorts sources location: /opt/local/var/macports/sources/rsync.macports.org/release/tarballs
--->  Updating MacPorts base sources using rsync

Willkommen auf dem RSYNC-server auf ftp.fau.de.
Nicht all unsere Mirror sind per rsync verfuegbar.

Welcome to the RSYNC daemon on ftp.fau.de.
Not all of our mirrors are available through rsync.


receiving file list ... rsync: link_stat "/tarballs/base.tar" (in release) failed: No such file or directory (2)
done

sent 4 bytes  received 9 bytes  5.20 bytes/sec
total size is 0  speedup is 0.00
rsync error: some files could not be transferred (code 23) at /BuildRoot/Library/Caches/com.apple.xbs/Sources/rsync/rsync-51/rsync/main.c(1404) [receiver=2.6.9]
Command failed: /usr/bin/rsync -rtzv --delete-after rsync://rsync.macports.org/release/tarballs/base.tar /opt/local/var/macports/sources/rsync.macports.org/release/tarballs
Exit code: 23
DEBUG: Error synchronizing MacPorts sources: command execution failed
    while executing
"macports::selfupdate [array get global_options] base_updated"
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