debian, tab completion failing

Not a big deal, but since the solution to this problem wasn't immediate to find, it's probably worth writing it down.

Symptom: when you try to tab complete a command, you see a message like this:

vi /et-sh: <( compgen -d -- '/et' ): No such file or directory

Cause: You're using sh, not bash, so even if tab completion is enabled on ~/.bashrc, it won't be available to you.

Solution: change the default shell for the current user from sh to bash with

chsh -s /bin/bash

That's it.