ERR-SYS-00007: Performance Issues with Fontconfig <= 2.12.92

Fc-Cache Algorithm Issues, Long Font Installation Times, and Unresponsive Desktop


With Fontconfig version < 2.12.92, an inefficient algorithm has been utilised with its Fontconfig cache generator (fc-cache), useful for caching font information, and speeding up font display in graphical applications. However, with larger collections of fonts installed - especially with larger CJK (Chinese, Japanese, and Korean) fonts like noto-cjk-fonts - the utility may require several minutes, or more to complete on slower devices (ARM boards, and older PowerPC-based Macintoshes), during which...

  • Graphical applications may not launch, or takes minutes to show its interface.
  • GNOME Shell in particular may lock up and require a system reboot, which may interrupt system updates or package installation, rendering the system unusable until these operations are manually resumed.

Possible Cause

It is difficult to digest the causation and the upstream solution to this issue. This is best described from the original upstream bug report, where a faster fc-cache implementation was worked on and merged at the end, ref.

Fixed Version

Updating to Fontconfig version > 2.12.6 resolves this issue.