When a user runs emacs (or any other program that uses fontconfig), acache is created in ~/.cache/fontconfig. This cache is not updatedautomatically after installing new fonts, and must be manually clearedout.
I guess this might be related to our use of Jan 1, 1970 as thetimestamps for all files in /gnu/store (which includes user profiles).
We should either modify fontconfig to detect a stale cache using amethod that works on Guix, or else notify the user that they must clearthe cache after installing ttf fonts.
Mark