Opening settings freeze the system
Using Manjaro 32-bit 18.0.0, if you selectively upgrade GTK from GTK 3.24.1 to 3.24.4 and then open Pamac settings, the window shows garbage and the hole system starts becoming unresponsive. As seen in this screencast.
It also causes garbage in other GTK3 applications, for example with XFCE.
At the time of the issue, the terminal echoes various times:
Pango-CRITICAL **: pango_layout_get_pixel_extents: assertion 'PANGO_IS_LAYOUT (layout)' failed
Gdk-WARNING **: Native Windows wider or taller than 32767 pixels are not supported