From https://github.com/gtk2hs/gtkglext/commit/57af428eb3661ca15eadbc0a30528bc6bce8f568
From: Xavier Dectot <xavier@wheredoibegin.fr>
Date: Tue, 15 Apr 2025 10:37:56 +0200
Subject: [PATCH] b

--- a/gtkglext.cabal
+++ b/gtkglext.cabal
@@ -50,11 +50,12 @@ Library
                         glib  >= 0.13.3.0 && < 0.14,
                         pango >= 0.13.2.0 && < 0.14,
                         gtk   >= 0.14.3 && < 0.15
+        cpp-options: -U__BLOCKS__ -DGLIB_DISABLE_DEPRECATION_WARNINGS
         if flag(have-quartz-gtk)
           cpp-options: -DHAVE_QUARTZ_GTK
         if flag(use-deprecated)
           cpp-options:  -DUSE_DEPRECATED_PANGO
-        cpp-options: -U__BLOCKS__ -D__attribute__(A)= -D_Nullable= -D_Nonnull=
+        cpp-options: -D_Nullable= -D_Nonnull=
 
         build-tools:    gtk2hsC2hs >= 0.13.9,
                         gtk2hsHookGenerator, gtk2hsTypeGen
-- 
2.49.0