[Nut-upsuser] usbhid-ups must use '-u root'

[Greg Vickers]

Hi all,

(Keeping this in a separate email from my first one so as to not make it 
horribly complex)

I've connected my Belkin F6C120auUNV UPS to my Debian 7.7.0 host via 
USB, and found that the usbhid-ups driver will not start unless I use 
the option '-u root', even when starting this driver as root:
root at monitor:/lib/nut# cat /etc/nut/ups.conf
[greything]
     driver = usbhid-ups
     port = auto
root at monitor:/lib/nut# ./usbhid-ups -a greything
Network UPS Tools - Generic HID driver 0.37 (2.6.4)
USB communication driver 0.32
Can't claim USB device [050d:0912]: could not detach kernel driver from 
interface 0: Operation not permitted
root at monitor:/lib/nut# ./usbhid-ups -a greything -u root
Network UPS Tools - Generic HID driver 0.37 (2.6.4)
USB communication driver 0.32
Using subdriver: Belkin HID 0.15
root at monitor:/lib/nut# ps aux | grep usbhid
root      4857  0.1  0.0  16888   712 ?        Ss   21:54   0:00 
./usbhid-ups -a greything -u root
root      4859  0.0  0.0   7836   880 pts/0    S+   21:54   0:00 grep usbhid

Is this expected behavior?  Seems like it should not be required, a 
quick google found this:
https://bugzilla.redhat.com/show_bug.cgi?id=488368 (not the same 
situation, but the short-term fix detailed works, i.e. use '-u root')

Thanks,
Greg