I compiled the latest version of tracker which needs gtk3 for configuring its preferences, so I installed gtk3.scm.
The preferences gui opens without problems but when I open the file chooser window I get this error:
GLib-GIO-ERROR **: Settings schema 'org.gtk.Settings.FileChooser' is not installed
so I did
sudo ln -s /apps/gtk3/share/glib-2.0/schemas/* /usr/local/share/glib-2.0/schemas/
and
sudo /usr/local/tce.installed/gsettings-desktop-schemas
and it works