I have developed my own custom gtk3 app in python, and I’m running into this issue. Here is gtk3-demo for example:
I’ve configured my gtk theme with home-manager like so:
gtk = {
enable = true;
iconTheme = {
package = pkgs.gnome.adwaita-icon-theme;
name = "Adwaita";
};
};
If its not the icon theme that is causing this issue, then what could it be?