[Nut-upsuser] Debian 9 : Can't open /etc/nut/upsd.users: Permission denied

[Roger Price]

I installed nut 2.7.4-5 on a fresh Debian 9.2.1 system.  I updated the 
configuration files, started nut in standalone mode, and got the error 
message

    Can't open /etc/nut/upsd.users: Permission denied

This is because the file has ownership and permissions

    -rw-------   1 root nut     91 Aug  3 11:44 upsd.users

I changed the ownership and permissions in /etc/nut/ to

    drwxr-xr-x   2 root nut   4096 Dec  7 18:32 ./
    drwxr-xr-x 140 root root 12288 Dec  9 12:39 ../
    -rw-r-----   1 root nut   1411 Dec  7 18:32 nut.conf
    -rw-r-----   1 nut  nut    290 Jul 14 20:16 ups.conf
    -rw-------   1 nut  nut    290 Jun 20 14:39 upsd.conf
    -rw-------   1 nut  nut     91 Aug  3 11:44 upsd.users
    -rw-------   1 nut  nut   1623 Jul  1 15:41 upsmon.conf
    -rw-r-----   1 nut  nut   1348 Jul  1 09:39 upssched.conf

and the error message disappeared. The nut:nut ownership seems to me to be 
more natural, and the root:nut ownership looks like a bug in the Debian 
package.

Roger