[GTALUG] YAD-Zenity-GTK on Pi - assistance needed

[Giles Orr]

YAD ("Yet Another Dialog") is a fork of Zenity - essentially a way to
display GTK+ dialogues from shell scripts.  I've chosen YAD because it
supports a couple things Zenity doesn't have, namely form buttons and
tabs.  I've created an ugly but functional interface that's meant to
go on a 3.5" touch screen on a Raspberry Pi.  But here's the problem:
by the time it gets on a screen that small, the buttons are too small
to reliably poke with a finger.  So I want to increase the font size.
All that was needed to fix that on my Fedora desktop was:

    # file: ~/.configs/gtk-3.0/settings.ini
    [Settings]
    gtk-font-name = Sans 32

And voila, 'yad' appears with a super-huge font.

However - this behaviour isn't replicated on the Pi.  It's an old(ish)
Debian stretch install on an old Pi B (not Pi 2 B, just "Pi B").  I'm
pretty sure that ~/.configs/gtk-3.0/settings.ini is the right file,
because when I mis-configured it, 'yad' complained loudly.  But it
ignores the font setting that works fine on another host.  I tried
'yad --font' which throws up what amounts to a GTK font selection
dialogue, and "Sans 32" is a valid font on the Pi.

Anyone got any ideas on this?

-- 
Giles
https://www.gilesorr.com/
gilesorr at gmail.com