Work around this by installing, alongside gnome-icon-theme, a system-wide
gtkrc containing the line:
gtk-icon-theme-name="gnome"
This avoids assertion failures regarding missing icons with GTK+
applications when executed outside of a Desktop Environment like GNOME
or XFCE.
Also remove x11/gtk+2/pkg/MESSAGE-main which is no longer needed.
Problem noticed by Patrick Keshishian
Discussed with and OK ajacoutot@
d88522e08f