Some themes don't have hover variants for button pixmaps.
It looks better visually to use the non-hover variants as fallbacks
rather than the built-in 6x6 pixmaps.
Add -Dsvg=disabled to your meson setup/configure command to disable svg
buttons even if the correct version of librsvg is available.
Note that regardless of this patch and the value of the 'svg' variable,
the build will gracefully fall back to not using librsvg if the correct
version is not available.
Helped-by: @01micko