Re: Authentication prompt when changing brightness

[Jesse Gibbons]

On Mon, 2019-10-07 at 06:25 -0700, David Wilson wrote:
> Hi all,
> 
> This is my first attempt at setting up Guix on my machine, so please
> forgive me if I've missed anything obvious here. I've noticed that any
> time a process tries to set the backlight brightness of my laptop, a root
> authentication prompt appears:
> 
> https://imgur.com/a/vlB7UtN
> 
> I've seen this both when using xfce4-power-manager and inexplicably on the
> GDM login screen when I didn't even press a brightness key. It definitely
> seems like some policy configuration isn't set up correctly but I'm not
> exactly sure how to correct it.
> 
> I've configured my machine to use only the XFCE desktop environment but in
> practice I'm actually using a custom .xsession to launch Emacs with EXWM
> as my window manager. I believe I also saw it when running in XFCE but I
> can't repro it now due to a separate issue with xfwm crashing when XFCE
> starts up.
> 
> Here's my current system configuration if it helps:
> 
> https://github.com/daviwil/dotfiles/blob/23743190b8f744f89a8a43da618057663
> 8246f72/guix/systems/zerocool.scm
> 
> I'm sure this must be a simple configuration issue so any help would be
> very much appreciated!
> 
> Thanks!
> 
> David
I have a similar problem. I see an authentication box when I try to adjust
screen brightness on the gdm screen, but not when logged into gnome. Does
this happen when you are logged in?

Just a guess, perhaps the "gdm" user can be added to the "video" group? I'm
not sure how to do that in the system configuration though.