gtk4 dark theme broken since upgrade to 23.11

[merspieler]

Describe the bug

Since the upgrade to 23.11, gtk4 apps no longer respect the set dark mode.

Steps To Reproduce

Steps to reproduce the behavior:

1. set dark mode for gtk4 via nix-shell -p glib --run "gsettings set org.gnome.desktop.interface gtk-theme 'Adwaita-dark'"
2. launch any gtk4 app via Dmenu or terminal
3. it's not in dark mode

Only way I got it into using dark mode was like this:
GTK_THEME=Adwaita-dark <program> but that's not feasible when using dmenu

Expected behavior

All gtk4 apps are in dark mode

Additional context

Add any other context about the problem here.

In case it makes a difference, I'm running i3wm under X.org.

Metadata

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

[user@system:~]$ nix-shell -p nix-info --run "nix-info -m"
 - system: `"x86_64-linux"`
 - host os: `Linux 6.1.67, NixOS, 23.11 (Tapir), 23.11.1779.cf28ee258fd5`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.18.1`
 - channels(root): `"nixos-23.11, nixos-unstable"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

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[alesya-h]

It's not just gtk4. For me it's mostly gtk3 apps with some exceptions, whereas gtk4 apps all work normally. I've tested the following apps: GTK3 (Tilix ❌ , Terminator ❌ , Meld ❌, Gnome Disks 🟢 ) and GTK4 (BlackBox 🟢 , Console 🟢 , Gedit 🟢 , Blanket 🟢). For apps that show in white style gtk inspector shows an unset theme, but setting it and/or toggling "Dark Variant" doesn't change anything:

[mannp]

For me, both gtk3 and gtk4 settings.ini had the following settings;

[Settings]
gtk-icon-theme-name=Adwaita
gtk-theme-name=Adwaita-dark
gtk-application-prefer-dark-theme=0

changing to;

[Settings]
gtk-icon-theme-name=Adwaita
gtk-theme-name=Adwaita
gtk-application-prefer-dark-theme=1

Made things dark again :)

[merspieler]

already had prefer dark theme, added the others as well now, programs are still white

[mannp]

Do you have gnome tweaks installed by any chance?

gtk-theme-name=Adwaita-dark, should be gtk-theme-name=Adwaita for me, will update.

[alesya-h]

@mannp adding those lines didn't fix it. To me it seems that the problem is with apps not being able to find Awaita Dark theme (or any theme at all, see inspector screenshots above)

[mannp]

@mannp adding those lines didn't fix it. To me it seems that the problem is with apps not being able to find Awaita Dark theme (or any theme at all, see inspector screenshots above)

Sure, I don't use inspector, but within gnome tweaks the adwaita dark theme is not specified separately now, it's just Adwaita for me.

[jtojnar]

Only way I got it into using dark mode was like this:
GTK_THEME=Adwaita-dark <program> but that's not feasible when using dmenu

This sounds like OP is using libadwaita-based GTK 4 apps, where changing the gtk-theme GSettings key (from org.gnome.desktop.interface schema) does not work.

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The rest of you are are probably encountering unrelated issue triggered by #278941.

In short, Adwaita-Dark should not be used these days since it is unmaintained. The aforementioned PR removes it from the default installation.

You should instead use the Adwaita theme shipped with GTK 3, which has dark theme built in (if you set gtk-application-prefer-dark-theme=1 in GTK 3 config).

For GTK 4 apps not using libadwaita, the theme is called Default, gtk-application-prefer-dark-theme=1 (in GTK 4 config) should work there as well.

For libadwaita-based GTK 4 apps, you need to set the color-scheme GSettings key (from org.gnome.desktop.interface schema) to 'prefer-dark'.

[merspieler]

tried all of those options, kdenlive for example... white

[jtojnar]

That is not a GTK app so no idea how it works there.