kde-gtk-config: GLib-GIO-ERROR **: No GSettings schemas are installed on the system

[ysndr]

Issue description

when attempting to save gtk styles in KDE Settings module kde-gtk-config systemsettings will crash with following error:

Apr 13 18:28:11 nixos xsession[2505]: (systemsettings5:3557): GLib-GIO-ERROR **: No GSettings schemas are installed on the system
Apr 13 18:28:11 nixos kernel: traps: systemsettings5[3557] trap int3 ip:7f5ef02bed91 sp:7fffe52c4320 error:0 in libglib-2.0.so.0.5400.3[7f5ef026f000+112000]

what is interesting is that most settings will actually be saved while others (such as prefering gtk3 styles) wont.

Steps to reproduce

1. open systemsettings5 > Application Style > GNOME Application Style (GTK)
2. make changes
3. hit apply
4. no point 4

Technical details

• system: "x86_64-linux"
• host os: Linux 4.14.32, NixOS, 18.03.131954.2569e482904 (Impala)
• multi-user?: yes
• sandbox: no
• version: nix-env (Nix) 2.0
• channels(root): "nixos-18.03, nixos-unstable-18.09pre133640.ea145b68a01"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs

[jtojnar]

If you run application trying to access GSettings, it needs to have the necessary schemas in XDG_DATA_DIRS. See #16285 (comment) and the commit below that for more info.

[ysndr]

Thanks for the info

So adding wrapGAppsHook to native build inputs of kde-gtk-config should be enough?

[jtojnar]

If the package contains something that can be wrapped, sure.

[ttuegel]

That package does not contain anything which can be wrapped. We would have to include kde-gtk-config into systemsettings and then wrap that so that everyone using KDE pulls in GTK. Or ask whoever wrote wrapGAppsHook to make it act differently.

[jtojnar]

@ttuegel What do you mean by wrapGAppsHook acting differently? How?

[ttuegel]

@jtojnar It would have to do something different with the schemas so that the wrappers are not required. The problem is that the wrapper goes only around an executable, but kde-gtk-config provides a plugin (shared library) that cannot be wrapped.

Something else I might be able to do is patch the provided plugin to modify the environment, if I can get the correct environment settings during the build.