Upon adding a GUI on top of a pre-existing cli-only install of
devuan-alpha-4, the functionality of suspend, hibernate, switch-users,
shutdown and restart were unavailable to the desktop user.
The easy solution for suspend and hibernate is to create a pkla file in
folder /etc/polkit-1/localauthority/50-local.d with contents:
[Allow locally logged in members of group 'power' to put the hardware in
suspend mode]
Identity=unix-user:*
Action=org.freedesktop.upower.suspend
ResultAny=no
ResultInactive=yes
ResultActive=yes
[Allow locally logged in members of group 'power' to put the hardware in
hibernate mode]
Identity=unix-user:*
Action=org.freedesktop.upower.hibernate
ResultAny=no
ResultInactive=yes
ResultActive=yes
The more complex solution is to create a group 'power', add desktop
users to that group, and then create the above file, but replacing
'unix-user:*' with unix-group:power'.
I don't yet have a working solution for 'switch-users', 'shutdown', or
'restart'.