ports.tar.gz update interval?

[Andrew Todd]

Like many people, I use MacPorts from behind a restrictive firewall
that blocks rsync. It's also somewhat slow, so to update my ports
tree, I have this configuration in ports.conf:

file:///Users/atodd/dev/macports/ports/ [default]

and I execute a script that looks like this:

#!/usr/bin/env bash

set -e
set -o pipefail
set -u
set -x

cd ~/dev/macports/
rm -rf ports*
wget http://www.macports.org/files/ports.tar.gz
tar xzf ports.tar.gz
sudo port upgrade outdated

Running it daily this week, I have always gotten this message:

Error: No ports matched the given expression

(Typically I only run it once a week, but I'm not used to the lack of updates).

Did everyone go on vacation this week, or is the tarball out of date? Thanks.