adding environment variables to /etc/config.scm

adding environment variables to /etc/config.scm

[Jonathan Lane]

Hello,

I have a laptop with Intel graphics and I need to set the environment
variable "COGL_ATLAS_DEFAULT_BLIT_MODE=framebuffer" to fix GPU 
corruption issues as described here:

https://wiki.archlinux.org/index.php/Intel_graphics#Troubleshooting
https://bugs.freedesktop.org/show_bug.cgi?id=88584

Unfortunately, it's supposed to go in /etc/environment, and that file
gets clobbered every time I reboot or run `guix system reconfigure`.  I
see that $GUIXSRC/gnu/system.scm does some logic to generate that file,
but I don't see an exported variable to manipulate from config.scm like
I do %desktop-services and the like.  What is the recommended way to add
global variables here?  It has to be a global variable because it alters
the behavior of the X server before gdm starts or my user logs in - I've
tested putting it in .profile and .bashrc to no avail.

Alternatively, this bug is not present on Wayland, so an update to make
gdm run via Wayland by default and expose Wayland sessions would solve
the root problem.

Thanks,

Jonathan Lane

Re: adding environment variables to /etc/config.scm

[Ludovic Courtès]

Hello Jonathan,

"Jonathan Lane" <jon@dorsal.tk> skribis:

> I have a laptop with Intel graphics and I need to set the environment
> variable "COGL_ATLAS_DEFAULT_BLIT_MODE=framebuffer" to fix GPU 
> corruption issues as described here:
>
> https://wiki.archlinux.org/index.php/Intel_graphics#Troubleshooting
> https://bugs.freedesktop.org/show_bug.cgi?id=88584
>
> Unfortunately, it's supposed to go in /etc/environment, and that file
> gets clobbered every time I reboot or run `guix system reconfigure`.

Indeed, on Guix System one is not supposed to modify config files in
place.

Instead, you declare every aspect of your system config in your
‘operating-system’ declaration, and then run ‘reconfigure’ so that it’s
in effect.

To add environment variables to /etc/environment, you would “extend”
‘session-environment-service-type’, like so:

  (simple-service 'cogl-variable session-environment-service-type
                  '(("COGL_ATLAS_DEFAULT_BLIT_MODE" . "framebuffer")))

The expression above provides a service that you can add to the list in
the ‘services’ field of your ‘operating-system’ declaration.

HTH!

Ludo’.

Re: adding environment variables to /etc/config.scm

[Jonathan Lane]

On Tue Sep 3, 2019 at 11:27 AM Ludovic Courtès wrote:
> Hello Jonathan,
 
> Indeed, on Guix System one is not supposed to modify config files in
> place.
> 
> Instead, you declare every aspect of your system config in your
> ‘operating-system’ declaration, and then run ‘reconfigure’ so that it’s
> in effect.
> 
> To add environment variables to /etc/environment, you would “extend”
> ‘session-environment-service-type’, like so:
> 
>   (simple-service 'cogl-variable session-environment-service-type
>                   '(("COGL_ATLAS_DEFAULT_BLIT_MODE" . "framebuffer")))
> 
> The expression above provides a service that you can add to the list in
> the ‘services’ field of your ‘operating-system’ declaration.
> 
> HTH!
> 
> Ludo’.

This worked perfectly, thanks!

Jonathan

--posted from Guix System, now with working Xorg