bug#23200: XFCE: selecting a style has no effect

[Ricardo Wurmus <rekado@elephly.net>]

Chris Marusich <cmmarusich@gmail.com> writes:

> I've noticed surprising behavior on a fresh install of GuixSD v0.10.0
> when using XFCE.  In XFCE, in the "Appearance" section of the settings,
> under the "Style" tab, if you select an alternate style (e.g.,
> "Xfce-kolors"), the color scheme does not actually get updated.  I
> expected the colors of the windows to change, but they did not.
>
> Is this expected?  Perhaps I'm missing something that needs to be done
> to apply the change, but it seems like it just isn't working.

Here’s what worked for me:

* install gnome-themes-standard into the system profile
* set GTK_DATA_PREFIX to “/run/current-system/profile”

The problem here is that GTK_DATA_PREFIX is not a list of directories in
which GTK+ should look for themes; it is just a single directory.  We
need to patch GTK+ to search through a list of directories instead.

~~ Ricardo