bug#57490: UPower ignores ‘critical-power-action’

["Ludovic Courtès" <ludo@gnu.org>]

As discussed on IRC with Tobias, UPower appears to ignore our
‘critical-power-action’ setting.  On my machine, I left the default
(‘HybridSleep’) but upowerd dismisses it and chooses ‘PowerOff’:

--8<---------------cut here---------------start------------->8---
$ guix system describe
Generation 198  Aug 29 2022 00:47:53    (current)
  file name: /var/guix/profiles/system-198-link
  canonical file name: /gnu/store/85441w3nzqv8lg04gm7601wi9np4qlw7-system
  label: GNU with Linux-Libre 5.18.19
  bootloader: grub-efi
  root device: label: "root"
  kernel: /gnu/store/a43ai5qi4vbgm2zywg4b60y71d7whccn-linux-libre-5.18.19/bzImage
  channels:
    guix:
      repository URL: https://git.savannah.gnu.org/git/guix.git
      branch: master
      commit: 3294fa2ba451c7d5ef42a5d9fac780877f364bc7
  configuration file: /gnu/store/lmqb5d0il8zydd0p0vz4kviaq1qg4n9m-configuration.scm
$ upower -d | tail -6
Daemon:
  daemon-version:  0.99.15
  on-battery:      no
  lid-is-closed:   no
  lid-is-present:  yes
  critical-action: PowerOff
$ sudo herd status upower-daemon 
Status of upower-daemon:
  It is started.
  Running value is 338.
  It is enabled.
  Provides (upower-daemon).
  Requires (dbus-system udev).
  Conflicts with ().
  Will be respawned.
$ sudo cat /proc/338/environ |xargs -0
PWD=/ UPOWER_CONF_FILE_NAME=/gnu/store/yq6zf8q2l2axy03d99pami3sxrk4784y-UPower.conf SHLVL=0 XDG_DATA_DIRS=/gnu/store/bnsf9il448hl5xjavbhq3rcx355svz2v-glib-2.70.2/share
$ cat /gnu/store/yq6zf8q2l2axy03d99pami3sxrk4784y-UPower.conf |grep Critical
PercentageCritical=3
TimeCritical=300
CriticalPowerAction=HybridSleep
--8<---------------cut here---------------end--------------->8---

Looking at the code, it could be because the ‘CanHybridSleep’ method
returns false, but why that would happen is unknown to me.

Thoughts?

Ludo’.