Have just realised this is not putting the udev rule in the correct location. Will try to fix soon

Please add an entry for this in nixos/module-list.nix otherwise the NixOS module isn't available for use! :)

And it looks like 1.4.4 is out, so might want to bump to that :).

And it looks like 1.4.4 is out, so might want to bump to that :).

I have bumped up the version number though for some reason I cannot work out it seems to be accepting the old sha256 hash. I don't think it should be doing this as if I purposefully break it then it says it is wrong and that it was expecting a hash which is not the one it is currently using. I've just checked and both hashes work in the derivation. Any idea what is causing this to happen and is it a problem @dtzWill

I believe my above observation was due to caching on my laptop, it is now fixed.

@dtzWill @jtojnar @symphorien is there anything else I need to do for this to be merged?

I've made the changes you suggested and I think I've managed to rebase everything @aanderse though can't see how to mark as resolved

LGTM :)

@alexarice I'm testing this out on a laptop but can't seem to get anything to happen...
brillo -L lists intel_backlight, but when I run any of the commands nothing seems to happen. Do you have a set of test commands you used that I can try?

brillo -A 0.5 and brillo -U 0.5 works for me. Do you get an error message or does nothing happen? I have also just realised I've been running wayland and haven't tested it on X
Edit: -G (get current brightness) -G -m (get maximum brightness) and -G -c (get minimum brightness) also work for me
Edit2: Could you also check your user is part of the video group and could you try brillo -A 0.5 -v 1 to turn on some error messages
Final Edit: pkexec /nix/store/48bg34xxcrqvizn026r5hvldd50dpcrh-brillo-1.4.4/bin/brillo -A 5 also works even when my user is not part of the video group though it would be a lot nicer if I didn't have to specify the full path for this to work
Actual final edit: I could patch the polkit file to not need the full path

@alexarice I made a mistake and it turns out running pkexec brillo -A 0.5 does work. If I run the command unprivileged (though my user has been added to the video group, logged out and back in), the command does not work and gives the following error:

brillo -A 0.5 -v 1
!ERR: src/file.c:191    file_read():    fopen: No such file or directory: '/home/andersea/.cache/brillo/backlight.intel_backlight.mincap'
!ERR: src/file.c:161    file_open():    open: Permission denied: '/sys/class/backlight/intel_backlight/brightness'
!ERR: src/main.c:24     main(): Execution failed

Interesting, I've done a bit of investigation and I think the following is happening:

• I believe you are getting a permission denied as you don't have services.udev.packages = [ brillo ]; in your configuration.nix. This should be set by the module but I don't know of a way to test modules without rebuilding my configuration off my local nixpkgs
• I looked at what was happening on mine and if I delete the file that doesn't exist on yours then It throws an error but works anyway
• I had set that file using brillo -rc -S 1 but I had done this on 1.4.3 where it worked correctly
• I now have an error about failing to write to that file when running the same command
• If I manually do 'echo 1 >> backlight.intel_backlight.mincap` Then everything works correctly.
• The code throwing the error has changed from 1.4.3 to 1.4.4, Maybe this is an upstream bug?

I have looked over the code and believe there could be an upstream error, should I revert this to 1.4.3 and submit an issue there?

I have had a bit more of an investigate and have submitted a merge request upstream, though I believe at the moment the only functionality which doesn't work is the minimum brightness setting and this can be manually set

* I believe you are getting a permission denied as you don't have `services.udev.packages = [ brillo ];` in your `configuration.nix`. This should be set by the module but I don't know of a way to test modules without rebuilding my configuration off my local nixpkgs

I installed the brillo module that you have here. I also tried bumping the version down to 1.4.3 and same error.

brillo -A 0.5 -v 1
!ERR: src/file.c:192    file_read():    fopen: No such file or directory: '/home/andersea/.cache/brillo/backlight.intel_backlight.mincap'
!ERR: src/file.c:163    file_open():    open: Permission denied: '/sys/class/backlight/intel_backlight/brightness'
!ERR: src/main.c:27     main(): Execution failed

I feel like I'm doing something wrong?

That is very strange, I just built my system against this fork with nixos-rebuild -I ~/nixpkgs switch and added only hardware.brillo.enable = true and I get the following output:

brillo -A 5 -v 1 
!ERR: src/file.c:191	file_read():	fopen: No such file or directory: '/home/alex/.cache/brillo/backlight.intel_backlight.mincap'

But my screen gets brighter.

For the error above I am trying to get a fix upstream https://gitlab.com/cameronnemo/brillo/merge_requests/4

Upstream issues have been fixed and I have moved this to 1.4.6.
@aanderse did you every figure out what was giving you permission errors?

It looks like you might want to nudge upstream on that 1.4.6 release...

~> brillo -V
brillo 1.4.5

https://gitlab.com/cameronnemo/brillo/blob/v1.4.6/src/light.h#L8

The issue persists. I have to assume I'm doing something wrong at this point. As a KDE user I don't actually need this program... so I'm going to leave it up to someone else to say whether the program works or not. It would be nice if at least one person other than @alexarice could confirm this works under X11 as expected.

Did you try if the program light works for you as that has near identical module definition. Have asked for the version to be bumped upstream

Did you try if the program light works for you as that has near identical module definition. Have asked for the version to be bumped upstream

@alexarice I have not and as I mentioned at this point I'm happy if someone else can confirm.

This pull request has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/prs-ready-for-review-may-2019/3032/48