@BobbyMarinov if you actually read the tip, it's not about using double-commiting at all and explains some of the troubles with it...
@janosgyerik no errors, but the autocomplete just didn't work :/ Using OS X 10.9.2
This path didn't work for me.
Following the guide from the MacPorts project worked however: https://trac.macports.org/wiki/howto/bash-completion
@SaberUK That's also an option, that's why I recommended creating an Disk Image, not formatting your main drive :)