Is there a way to debug fontconfig's font selection?
I did a dist-upgrade on my Sid laptop this morning and upon restarting
icewm its fonts had vanished. It only happens with one icewm theme, so
it would seem to be a font selection problem. But I can't figure out
what changed to cause the problem. The problem was discussed on the
icewm mailing list and there's a bug against the icewm package.
I assume the X experts know how to debug problems like this. Fonts are
a common topic on debian-user, and there's a lot of HOWTOs and setup
examples, but I have not found anything that helps me debug problems.
It's my basic lack of understanding of X, of course. Do any of you know
of a good font _debugging_ howto?
For example, in icewm it seems like this font family:
is the problem. I probably don't have that font installed, but I assume
previously there was a font substitution happening that worked, and
now there's a different font substitution happening that doesn't
display. But that's just my guess.
Is there a way to debug that font selection process? My limited
understanding is the application uses fontconfig to find a font, then X
for rendering that font.
I think it would be very helpful for me (in debugging problems like
this) to be able to watch the font selection process for an application.
For example, I would like to watch what font icewm is requesting, and
what actually gets selected and rendered.
Is there a way to do that?
And a similar request to fontconfig list some time back: