Bug#862732: cups-filters: unreadable file /usr/lib/cups/backend/serial

[Till Kamppeter <till.kamppeter@gmail.com>]

On 05/16/2017 02:48 PM, Didier 'OdyX' Raboud wrote:
> … but I think it would work with a chmod 744.
> Alexander: do you have a serial printer; and could you test?
> Till: as you're the initial committer of that code; any opinion ?

The "serial" backend is a CUPS backend which has to run as root to 
correctly work. CUPS decides which backends run as roo by the file 
permissions of the backends. One of the backends which comes with CUPS 
and has to run as root is the "usb" backend:

-r-xr--r-- 2 root root 34808 Mar 23 14:55 /usr/lib/cups/backend/usb

This backend is still world-readable and only omits the execution bit 
for anyone else than root itself (644 permissions). This should also 
work with the "serial" backend in cups-filters.

   Till