Comment 61 for bug 190848

https://bugs.launchpad.net/ubuntu/+source/gnome-terminal/+bug/190848/comments/40

> vte uses xft for font backend, while others uses pango.

Yes, and Pango uses cairo.

The problem does not appear with cairo, because fontconfig settings sometimes
do not get respected in cairo due to

https://bugs.freedesktop.org/show_bug.cgi?id=11838

which causes other problems, reported in bug 200707, bug 209256, and bug
293643.

> This may be a bug of xft, which doesn't follow xsetting.

libXft was the original library that effectively defines the interaction of
fontconfig and Xft X resource settings. IMO it is a bug that cairo does not
emulate this behavior consistently.