bug#14401: su - nobody -c emacs gives "Could not open file: /dev/tty"

[Stefan Kangas]

jidanni@jidanni.org writes:

> Odd,
>
> # (unset DISPLAY; su - nobody -c emacs)
> No directory, logging in with HOME=/
> emacs: Could not open file: /dev/tty
>
> doesn't work anymore. One needs two steps,
>
> # (unset DISPLAY; su - nobody)
> No directory, logging in with HOME=/
> nobody@jidanni2:/$ emacs
>
> Also one can test with su nobody with no -.

I can't reproduce the recipe easily since the user nobody has no
password on my machine.

Is this a bug in Emacs though?  To me, it seems more like some quirk
of how su works in this case.  Does the above work with other
programs, for example "top" or something?

Best regards,
Stefan Kangas