Unable to selfupdate; rsync command works outside of ports

[adam.attarian@…]

Greetings. When I try to self update ports, I receive and HTTP error message:

[09:45 user@host ~] > sudo port -v selfupdate
--->  Updating MacPorts base sources using rsync
rsync: server sent "HTTP/1.0 500 handshakefailed" rather than greeting
rsync error: error starting client-server protocol (code 5) at /SourceCache/rsync/rsync-45/rsync/main.c(1398) [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: 5
Error: Error synchronizing MacPorts sources: command execution failed
Error: /opt/local/bin/port: port selfupdate failed: Error synchronizing MacPorts sources: command execution failed
sent 36 bytes  received 69 bytes  70.00 bytes/sec

The rsync command works outside of the selfupdate:

[09:45 user@host-mitll ~] > sudo  /usr/bin/rsync -rtzv --delete-after rsync://rsync.macports.org/release/tarballs/base.tar /opt/local/var/macports/sources/rsync.macports.org/release/tarballs

receiving file list ... done
total size is 27013120  speedup is 257267.81 `

I am behind a proxy:

[09:52 user@host-mitll ~] > sudo env | grep http
http_proxy=http://xxx.xxx.xxx.xxx:8080

https_proxy=http://xxx.xxx.xxx.xxx:8080

Any ideas? Apologies for the formatting; I couldn't get the wikiFormatting to do its thing. Basically, the rsync command doesn't work within selfupdate, but does if I just do it manually. This complicates my debugging.

[ryandesign (Ryan Carsten Schmidt)]

Why is the rsync connection going through an http proxy? Is that normal / is that supposed to work? I've never heard of that.