I think I've found an issue in fontconfig's SlackBuild.
Looking inside /etc/fonts/conf.d (after a fresh install) I've noticed that every link's target is something in '../conf.avail', es.:
lrwxrwxrwx 1 root root 30 Feb 1 19:32 40-nonlatin.conf -> ../conf.avail/40-nonlatin.conf
This is not true for 10-scale-bitmap-fonts.conf (provided by the fontconfig package):
lrwxrwxrwx 1 root root 48 Feb 1 19:32 10-scale-bitmap-fonts.conf -> /etc/fonts/conf.avail/10-scale-bitmap-fonts.conf
The final result is obviously the same, but I was curious about this exception, since it could reveal an unintended behaviour.
The cause of this difference seems to be the fact that this specific link is not managed by the SlackBuild (see section with the comment: 'Set up the default options in /etc/fonts/conf.d:').
In fact, fontconfig's Makefile deals with the creation of these links itself (at compilation time); then the SlackBuild re-creates the links using the '../conf.avail' format. This happens for every link except that specific one.
The full list (taken from fontconfig's sources, specificly from conf.d/Makefile.am) should be:
CONF_LINKS = \
Of course, if Pat's intention was instead to remove that specific link from the default list, the problem has to be addressed in a different way.
What do you think? I'll email Pat about this ASAP.