Upower based Hibernation not working in fresh-install Slackware64-current

I installed slackware-current yesterday after like 2 years. After setting up
everything I noticed Suspend (untested) nor Hibernate is not working. It used to
be that typing

Code:loginctl hibernate used to hibernate the machine, given user is in the 'power'
group, but that's not the case anymore. It shows no output.

According to the slackware-wiki there are two ways to hibernate, Upower and Hal.
pm-utils is not installable anymore, Hal is not present (depricated) and Upower throws an error.

Code:$ dbus-send --system --print-reply --dest="org.freedesktop.UPower" \
/org/freedesktop/UPower org.freedesktop.UPower.Hibernate

Error org.freedesktop.DBus.Error.UnknownMethod: No such method iHibernateiOther system info:

Code:uname -a
Linux hostname.example.net 6.9.8 #1 SMP PREEMPT_DYNAMIC Fri Jul
5 14:02:34 CDT 2024 x86_64 11th Gen Intel(R) Core(TM) i5-1135G7 @
2.40GHz GenuineIntel GNU/Linux