$ sudo su -
# du -sh /opt
6.4G  /opt
# port clean -f --all installed
---> Cleaning apr
---> Cleaning apr-util
...
# du -sh /opt
6.3G  /opt
# port -f uninstall inactive
--->  Uninstalling autoconf @2.62_0
--->  Uninstalling automake @1.10.1_0
...
# du -sh /opt
5.4G  /opt