Tab path completion does not work (at least on Ubuntu and AFAIK Arch) with

sudo mount <whatever>

The iso file I am trying to mount is not in /etc/fstab. If I just type

mount <whatever>

the completion works (but of course the command fails as I am not root). Apparently it is sudo that breaks it.

How can make completion work with sudo?

It is surprising that with

sudo umount <whatever>

completion works. How is it achieved? Does it look into /etc/fstab?

Solution: I just put a shell script into /usr/local/bin that calls sudo mount ... with the arguments passed to it. Completion works when calling this script since there is no sudo in the way.