剛才突然發現，做 MacPort 的 selfupdate 時會失敗，
上次做還 OK 啊..?

＄sudo port -f selfupdate
Warning: No index(es) found! Have you synced your source indexes?
---> Updating the ports tree
Error: Synchronization of the local ports tree failed doing rsync
Error: /opt/local/bin/port: port selfupdate failed: Couldn't sync the ports tree: Synchronization of 1 source(s) failed

測試一下公司網路：

$ telnet rsync.macports.org 873
Trying 17.254.20.244...

嗯，Port 873 出不去！
沒想到，公司 MIS 連 rsync 的 port 也給封了！真是麻煩，
費了一番功夫後，
終於可以做 selfupdate 了：

$ sudo port selfupdate
Warning: No index(es) found! Have you synced your source indexes?
---> Updating the ports tree
---> Updating MacPorts base sources using rsync
MacPorts base version 1.9.2 installed,
MacPorts base version 1.9.2 downloaded.
---> MacPorts base is already the latest version

The ports tree has been updated. To upgrade your installed ports, you should run
port upgrade outdated