GTK3 CUPS printing fixed

The title "Cannot print documents from Firefox" was posted to the forum:

https://forum.puppylinux.com/viewtopic.php?t=6437

...see my discovery further down.

Amazing, how long ago since the Dunfell-series had the first release? In all of that time, have not been able to from from GTK3-based apps.

For Firefox, I always print to PDF, then use Evince PDF viewer to print the PDF. Evince, being GTK2-based can print.

Yes, I discovered that the 'gtk+3' package in OpenEmbedded defaults to not having CUPS support. I modified the recipe, and recompiled it, and tested the result. Voila, FF now prints!   

Tags: easy