debugging an Ada program that use gntkada: cannot load a pixbuf, gdk-pixbuf-error-quark 3.

[fdesp87]

Installed under the same basedir: latest gnat, gprbuild, gnatstudio and gtkada. No error/warning messages during installations.

Trying to debug (with gnatstudio) an Ada program using gtkada, the result is

(bpl8ui:13698): Gtk-WARNING **: 18:33:05.863: Could not load a pixbuf from icon theme.
This may indicate that pixbuf loaders or the mime database could not be found.
**
Gtk:ERROR:../../../gtk/gtkiconhelper.c:495:ensure_surface_for_gicon: assertion failed (error == NULL): Failed to load /home/opt/GNAT/14.2.0-1/share/icons/Adwaita/16x16/status/image-missing.png: Unrecognized image file format (gdk-pixbuf-error-quark, 3)
Bail out! Gtk:ERROR:../../../gtk/gtkiconhelper.c:495:ensure_surface_for_gicon: assertion failed (error == NULL): Failed to load /home/opt/GNAT/14.2.0-1/share/icons/Adwaita/16x16/status/image-missing.png: Unrecognized image file format (gdk-pixbuf-error-quark, 3)

OS is ubuntu 24.04.01 LTS
gtk-3.0

GnatStudio is OK when debugging programs that don't use gtkada. Of course, all directories under basedir are provided, including share/icons/Adwaita