Has anyone figured out how to customize a .desktop file for a flatpak app? I want to change the GTK theme for a single app which can be done by setting the GTK_THEME env variable when launching the app.
So I tried to copy the desktop from /var/lib/flatpak/exports/share/applications/org.gnome.Podcasts.desktop to ~/.local/share/applications/org.gnome.Podcasts.desktop and then editing it and after that running update-desktop-database but it doesn’t work. I also tried rebooting and it doesn’t work. And I tried to edit the original file as well.
It appears that those desktop files aren’t used when launching the app from the home screen but I can’t figure out what is file/config is used. According to this https://github.com/flatpak/flatpak/issues/1286 you should be able to put the desktop files in ~./local/share/applications and have it work.
Also for me the XDG_DATA_DIRS variable is not set, so I tried to set it but I wouldn’t recommend doing that because that gave me a black screen instead of a login screen. Luckily I was able to ssh to the phone and remove it.