[tc@box:~$ cd /usr/local/libexec/
tc@box:/usr/local/libexec$ ls -l dbus*
lrwxrwxrwx 1 root root 67 Feb 10 08:18 dbus-bash-completion-helper -> /tmp/tcloop/dbus-glib/usr/local/libexecdbus-bash-completion-helper
lrwxrwxrwx 1 root root 60 Feb 10 08:18 dbus-daemon-launch-helper -> /tmp/tcloop/dbus/usr/local/libexec/dbus-daemon-launch-helper
tc@box:/usr/local/libexec$ cd /tmp/tcloop/dbus/usr/local/libexec/
tc@box:/tmp/tcloop/dbus/usr/local/libexec$ ls
dbus-daemon-launch-helper
tc@box:/tmp/tcloop/dbus/usr/local/libexec$ ls -l
total 34
-rwsr-x--- 1 root root 34692 Sep 20 14:01 dbus-daemon-launch-helper
tc@box:/tmp/tcloop/dbus/usr/local/libexec$ devkit-power
(devkit-power:7846): devkit-power-gobject-WARNING **: Couldn't enumerate devices: Failed to execute program /usr/local/libexec/dbus-daemon-launch-helper: Success
tc user can't execute it i think that's the problem
tc@box:/usr/local/libexec$ sudo chmod 4755 dbus-daemon-launch-helper
tc@box:/usr/local/libexec$ devkit-power -e
/org/freedesktop/DeviceKit/Power/devices/battery_BAT0
/org/freedesktop/DeviceKit/Power/devices/line_power_AC0