Jesse,

Jesse Gibbons wrote:
> My Librem 13 laptop battery lasts much longer with a lower 
> screen
> brightness. When it runs gnome on guix (and I haven't tried any 
> other
> de) I have to turn down the brightness every time. This is not 
> so with
> my other partition running PureOS. Is there a way to configure a
> default screen brightness in guix/gnome?

Guix doesn't have a notion of ‘default’ screen brightness because 
it doesn't know anything about brightness.

My guess is that PureOS uses systemd; systemd provides a 
backlight.service that reads the backlight brightness at shutdown, 
stores it to disc, and writes that value back to the device at 
next start-up.

It would be a relatively trivial service to add, but that hasn't 
been done yet :-)

We do already provide a simple, script-friendly abstraction tool¹:

  $ guix install light
  $ sudo light -S 50 # percentage

It can even run setuid.

Kind regards,

T G-R

[1]: As opposed to manually reading and writing `find /sys -path 
*backlight*brightness*`.