ttf-dejavu 2.37 will change the way fontconfig configuration is installed. In
previous versions the configuration was symlinked from
post_install/post_upgrade, the new version will place the files inside the
package like it is done in fontconfig now.
For more information about this change: https://bugs.archlinux.org/task/32312
To upgrade to ttf-dejavu 2.37 it's recommended to upgrade the package on its
own: pacman -S --force ttf-dejavu
URL: https://www.archlinux.org/news/ttf-dejavu-237-will-require-forced-upgrade/