hey,
after trying to upgrade to polkitd 124-1devuan1, i get the same apt 
error as bug #718.
systemd-standalone-sysusers was installed while trying upgrade :
apt policy systemd-standalone-sysusers
systemd-standalone-sysusers:
   Εγκατεστημένα: 255.4-1+b1
   Υποψήφιο:      255.4-1+b1
   Πίνακας Έκδοσης:
  *** 255.4-1+b1 500
so, i've purged systemd-standalone-sysusers completely, and afterwards 
polkitd was installed/configured correctly.
apt policy polkitd
polkitd:
   Εγκατεστημένα: 124-1devuan1
   Υποψήφιο:      124-1devuan1
   Πίνακας Έκδοσης:
  *** 124-1devuan1 500
         500 http://deb.devuan.org/merged ceres/main amd64 Packages
         100 /var/lib/dpkg/status
      123-3devuan1 500
         500 http://deb.devuan.org/merged testing/main amd64 Packages
just notifying here, not sure if i should open a new bug report (?)
best,
d