MSYS2 update seems to mess up GTK3 and/or GtkAda

General
1

Today I updated my MSYS2 installation, which has also GTK3 installed, for use in combination with Gtkada. After the update, which transpired to be a complete MSYS2 upgrade, the installed MSYS version is:

$ cat /proc/version
MINGW64_NT-10.0-19045 version 3.6.7-f2802c5f.x86_64 (runneradmin@runnervmixnmc) (gcc version 15.2.0 (GCC) ) 2026-03-15 08:40 UTC

and the installed GTK3 version is:

$ pacman -Ss mingw-w64-x86_64-gtk3
mingw64/mingw-w64-x86_64-gtk3 3.24.52-1 [installed]
    GObject-based multi-platform GUI toolkit (v3) (mingw-w64)

Now, when running Gtkada apps, before and after recompiling Gtkada and the Gtkada apps, they all fail with these messages:

(motd.exe:2412): GLib-GObject-CRITICAL **: 13:49:08.929: cannot register existing type ‘GdkPixbuf’
(motd.exe:2412): GLib-GObject-CRITICAL **: 13:49:08.929: g_type_add_interface_static: assertion ‘G_TYPE_IS_INSTANTIATABLE (instance_type)’ failed
(motd.exe:2412): GLib-GObject-CRITICAL **: 13:49:08.929: g_type_add_interface_static: assertion ‘G_TYPE_IS_INSTANTIATABLE (instance_type)’ failed
(motd.exe:2412): GLib-CRITICAL **: 13:49:08.945: g_once_init_leave_pointer: assertion ‘result != 0’ failed
(motd.exe:2412): GLib-GObject-CRITICAL **: 13:49:08.945: g_object_new_valist: assertion ‘G_TYPE_IS_OBJECT (object_type)’ failed

Then the app hangs, and must be stopped with the MSWindows task manager. Anybody having the same problem? Or better, a solution?

2
  1. How many versions of Gtk do you have installed? In which order are they searched? E.g. Gnat Studio comes with a copy of Gtk. Then there is Alire.
  2. Did you rebuild GtkAda from the sources? AFAIK MSYS does not have GtkAda packaged. C libraries have tendency not to be backward compatible but linking OK.

P.S. For installing GtkAda under Windows see.