Bug#909395: upgrade-reports: missing sbin in root path

Package: upgrade-reports
Severity: important

Dear Maintainer,

Not really sure where to submit this but upgrading to buster via instructions at
https://wiki.debian.org/DebianTesting
resulted in a system that would boot fine, but when i went back in to aptitude afterwards I noticed
/sbin (and its subdirectories, eg /usr/local/sbin:/usr/sbin:/sbin ) was not in root's path.  This meant 
if I used 'su' to log in to root, to install/upgrade/whathaveyou ...ldconfig, 'shutdown' among other 
things was not in the path.

I've now upgraded 2 systems from stable to buster and both did the same thing.

adding 

PATH=$PATH:/usr/local/sbin:/usr/sbin:/sbin

to .bashrc for root (which was empty) made at least installing/upgrading via aptitude work...but there
wasn't much indication that I had to do this anywhere.  

If this is something new that we have to do for buster, it should be in the instructions

-- System Information: 
Debian Release: buster/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.18.0-1-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_CA.UTF-8, LC_CTYPE=en_CA.UTF-8 (charmap=UTF-8), LANGUAGE=en_CA:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled