To reduce the number of system dependencies, we statically link a version of fontconfig into (some of) our shipped programs. This version of fontconfig is most often not binary-compatible with the system fontconfig, especially the fontconfig cache files. fontconfig, to it's credit, does support versioned cache files, and will support multiple different version cache files in the same cache directory.
The tl-fontcache tool created in bug 7159 is a tool that lets fontconfig create these caches while also giving the user some feedback on what's going on via an X11 window. It's integrated into the ThinLinc session startup, which in practice leads to a user-specific cache being created, unless there is a system cache already present.
To reduce startup time and resource usage, a system administrator would then want to generate a system cache to avoid having each user creating their own generate per-user caches. However, as tl-fontcache requires X11, it's difficult to run as a scheduled task from cron or triggered from package upgrades.
It would be nice if we could offer a way for the system administrator to generate the system caches in the right format for other ThinLinc programs.
The font cache problem is further amplified by having multiple agent servers with shared home directories. According to customer reports, when a user ends up on a new agent server, the font caches will be regenerated.
This bug does cover similar ground as bug 7169 in that a solution for 7169 will either eliminate the underlying problem for this bug, or by also including a solution for this problem.