Portmaster tries to build the update in the wrong order. Right order for me was (depend on which packages are installed): rubygem-glib2 rubygem-gobject-introspection rubygem-gio2 rubygem-gdk_pixbuf2 rubygem-pango rubygem-gdk3 rubygem-gtk3 rubygem-atk Maintainer of portmaster informed via Mail.