I'm running latest Arch, have GNOME and Fluxbox and my main windows manager is Fluxbox. I wanted to manage my power settings in Fluxbox and i added gnome-power-manager in startup but is says there isn't a command like that. I checked if gnome-power-manager is installed with pacman and it says it is. Note when i open power settings in GNOME shell environemnt there is no 'close lid' option.
Note : Fixed My main intention was to use this power manager to manipulate the laptop's state when i close the lid, press the shutdown button etc. I fixed this with instaling xfce4-power-manager.