(pagecurl) CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
running Filters->Distorts->Pagecurl... from gimp-2.99 built with meson produces this CRITICAL:
(pagecurl:30818): GLib-GObject-CRITICAL **: 07:40:37.550: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
This is because meson.build produces a gresource.xml whose prefix is '/org/gimp/icons' whereas pagecurl.c looks for a '/org/gimp/pagecurl-icons'
Changing meson.build to generate the same prefix, suppresses the warning and the dialog shows an icon.